# Quantitative Airstone Test. an end to the hype



## legallyflying (Aug 23, 2011)

OK peeps.So in an effort to finally find out the difference between all the different air stones on the market and everyone's personal preference I decided to borrow the extremely expensive DO meter from work and put 7 different air stones to the test. 

*THE STONES *
OK we have an assemblage of the common airstones. 


we have the following:
*4" round bubble disc.* This is a flat disc with a grey sintered stone. the airlline attaches to the side and it stays on the bottom. they run about $8 online. 

*6" blue airstone*..these are the common cheap airstones that are available everywhere. they are dirt cheap around $1. They are made out of fragile blue stone that is known to disintegrate and fall apart after about 6 moths. 



*micro diffuser.* These are insanely expensive I have the smallest one at it cost me $20 online. theya re made from a very high quality material that is very hard and has very tight pores. The tight pores make llots of tiny tiny bubbles. They also creat a lot of back pressure on your pump which means it works harder and less air passes through the stone. These things would likely last forever. The hype is that the extremely small bubbles infuse more air into solution. 

* 4" blue airstone*- smaller version of the common 6" blue airstone detailed above.

*2" round cylinder airstone,* I dig these things, they have a ton of surface area, they are tough (tougher than the blue airstones, they are heavy, and they pass a shit load of air. 

*2-6" blue airstones on a single hose, * pretty self explanatory. some people run two stones in one bucket. wanted to see if there is something to that. 

* 4' bubble hose.* these are super cheaply made hoses with tiny holes in them that diffuse the air. I hate this thing, mostly because of the two I bought, one had inets on both ends. and the other one had an inlet so narrow that I had to use a pipe cleaner to actually clamp on the airhose. ANNOYING. 

*THE TEST*

Pretty simple. I had 6 4 gallon buckets and one five gallon bucket all filled with equal amounts of water. All the stones are driven by a large, 110 L/min commerical air pump. Its a big bad ass pump. The hoses are connected to a 12 outlet splitter. All but two of the 12 outlets had air stones on them. I opened the empty ones just a little bit as to simulate a "normal" pump. 

I ran the stones for about 10 minutes, then shut them all off, and then measured the DO levels. I then added an equal amount of hot water to each bucket to test at a higher temperature, then did it all over again to test it at an even higher temperature. 

A word about the DO meter. Although it is a high sensitive device and it was calibrated, much like a ppm meter, it is prone to drift around a little bit. I did my best to let it settle down and take the correct measurement. 

I measured DO content at the following temperatures.. 67.5, 77, and 82.5 degrees F.

*RESULTS*
Like a proper geek, I put the results in a excel spreadsheet and made a chart..just easier in the end. All results are in ml/L 



Here are some pictures of the stones "in action" 


*Discussion *
So as you can see, there is barely a difference between measured DO levels between the different stones. There was a slight difference between them but we are talking about tenths of a ml. There were a couple stand outs, and losers. The 4" blue stone did score the lowest at every temperature. Also, somewhat surprisingly the dual 6" blue airstones actually performed WORSE than the single 6" blue stone. 

Also of note was the "super mega micro diffuser" the gold standard of airstone..I mean, its got micro fucking bubblles man! ..scored middle of the pack. Going to pass on more of those. 

The 4' bubble line or whatever, despite the fact that it tested well, I'm somewhat leary of the results. I filled that bucket after the first round of testing so the water may have been a little colder. looking at how much air it was moving, I thought to myself that there is no way the readings were correct. Plus, it is a cheaply made piece of shit that the air hose doesn't even fit on without tying it on.. 

Some other factors to think about..

The 6" blue stone and the 2" round stone moved much more water than all the other stones, it was visibly more. I mean the water was just boiling. The lowest water movement came from the bubble hose and the micro diffuser.

I am using a pretty strong pump, a really strong pump really. The commercial pumps are pretty awesome and if you have a couple of reservoirs or buckets, they are wellworth it. I think that 110 cost me $80 online. That's a 1/4ounce of bud people...just spend the money. My point being that the airstones may perform different with lower airflows. But if you can get the same results by saving shit tons of money on the actual air stones..it may be worth it to buy a proper airpump. 

*CONCLUSION*

If you look at the results, you can see the single biggest factor is actually the temperature of the water. Which is not a huge surprise as warmer water holds less air in solution. If you have individual buckets, insulation is probably the best bet. I have a central reservoir (ebb/flow controller) so I can empty the buckets every couple hours and chill the water for 15 minutes using a dehumidifier coil and pump it back into the buckets. 

What am I going to do for airstones? Well its pretty obvious to me is the cheap old standby..the 6" blue airstones. They are a buck a piece so when your done with a cycle, you can simply pitch them and buy new ones. For me that means $16 every 3 months as opposed to $320 for 16 of the micro diffusers.

The 2" round stones are also a favorite of mine. They scored well and they moved allot of air and water. They are much more durable than the blue stones. They do clog up after 2 months in organic nutes, but I dunked them in strong bleach water and they came right back to life. I am not going to use 2 airstones like I previous thought of as they moved less air and water than a single stone. Why? likely due to reduced pressure. 

I'm actually going to sell the diffuser on e-bay. It is simply not worth the money I paid for it. 

I hope you found the test informative and helpful. I was actually pretty surprised at how even the scores were. Seems like everyone always hemms and haws over which air stone to use when in actuality, it doesn't matter a how lot.

Cheers and happy growing.


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## Mauler57 (Aug 23, 2011)

Always good to see a comparisons and reports on anything that will save me $$$ and optimize my grow conditions. REP+ my friend


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## batf1nk (Aug 23, 2011)

Good information here, thanks for clearing up some of the grey areas. +rep


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## SHABOOGY1 (Aug 23, 2011)

Thanks a ton for taking the time out to run the test on the bubblers... I was considering upgrading to diffusers but now i see i can use the money for a stronger pump and continue with the 2" rounds... I hate spending money on hype... Again,,, THANKS!!!


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## EvlMunkee (Aug 23, 2011)

Good idea.
I have used most of them and I eventually settled on the 2" x 4" stone. You are right ..they are very sturdy and will last quite a few grows.
Appreciate your efforts! 

rep for ya


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## medicine21 (Aug 23, 2011)

Great, work!!! +rep There is something to be said about the size of the bubbles though. I remember reading user "fatman" thread, who has also done extensive testing on this topic over at thcfarmer and the size of bubbles matters. As far as I remember he said that smaller bubbles are good because the DO in them is easier taken in by the roots and the bigger bubbles are better because they spread the roots thus allowing more root surface area to be exposed to DO. I think there was also some discussion about the challenge of using the DO meter and constant calibrations would be required as well as water needed to be running past it, i.e. in a current, but I can't recall the details.

Since your pump is so powerful and the results so close together, the conclusion that I draw from your results is that the airpump power is much more important for DO levels than the airstone. Do you have a small airpump you can run this test on?


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## legallyflying (Aug 23, 2011)

medicine, my thoughts on the little bubbles. While given the same volume of air, more smaller bubbles would have more surface area for gas exchange, the micro pore diffuser is soo tight that it is actually restricting lots of airflow. The down side of this is that the pumps will draw mor amps, become hotter, and in theory, wear out faster. How the air interacts with the plant roots is a good point but once that I don't have many theories on. 

One important thing is that we are measuring dissolved oxygen, that is oxygen in solution, not bubbles. Plants should be able to take up oxygen that is not in sollution..as that is how the do it in soil, but experience has sown they they don't NEED to in DWC as dissolved O levels have been shown to be accurate. My big theory is that given the amount of air that is being pumped in, all the containers were approaching the maximum DO levels at a given temperature. That is why the bars are so even given each temperature test. The actual differences could be do to meter calibration and the flowing water requirement but I did calibrate before each temperature run, swirled the meter when taking measurements, and took several measurements in each bucket. The results or numbers that I put in the chart represented the overall trend for each stone as even though the measurements floated around a little (by about .2), there was a difference in them. I'll googe disolved oxygen maximums given temperature a little later. I am essentially at sea level here.


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## BendBrewer (Aug 23, 2011)

Saw this in the Tea Thread and still love it. Wish you had a 4" cylinder stone like the 2" ones you like as that is what I use.

But great work and write up!

Cheers.


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## tip top toker (Aug 23, 2011)

Still reading but my very first thought is that unless they are tested on separate pumps and not connected to one on a slitter, then the results are not accurate surely. Unless all of the stones used create the exact same pressure power requirement thing on the pump. That is to say i have 2 stones, 1 has large holes and will allow lots of air out, another is rather the opposit, when connected to the same pump via a plitter the latter stones becomes nearly useless as all the air simply opts for the easier route out being the former stone. 

still reading though and kudos for the experiment none the less.

Personally i've always called bullshit on the statemeents of must be frothing, as amny bubbles as possbile. Most of my airstones are a year odd old and are blocked up to no end, barely a handful of bubbles escape, my plants grow just as they do when the stones were brand new.

http://tinypic.com/player.php?v=24l8unq&s=7
That's me best stone in action in a 40L res


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## RawBudzski (Aug 23, 2011)

what about those "micro-bubble" airstones. Oxyponic Systems


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## legallyflying (Aug 23, 2011)

ok,so I checked out DO maximums at a given temps ....http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm

There is no elevation given for those rates but in general, they track exactly with my measured results... 

67 degrees...9.26 ml/l
77 degrees...8.24 ml/l
83 degrees...7.81 ml/l

So again, big stones, little stones, big or little bubbles.. we were able to achieve maximum do rates with a $1 stone and a good pump. I would venture that a higher o flow rates in the cheaper stones and resulting increased flow and "turnover" in the water would be more beneficial than simply having more smaller bubbles. The reason being that the moving water cold indeed "push" around the roots and recharge o2 rates adjacent to the roots. As plants mature and the root ball becomes tighter, this would make a greater difference. 

But at some point we are splitting hairs though. Many growers would do better to limit bacteria growth in warm solutions that absorb oxygen. Or better yet, focus their energy on keeping room temps and humidity in check. Take away, buy a big pump, a big box of cheap stones and "set it and forget it".

BTW, for those that don't know, you can check how your airstone is flowting simply by putting your hand on the bucket. the difference between properly flowing, clogged, and hose came off can easily be felt by the frequency and intensity of the vibrations.


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## RawBudzski (Aug 23, 2011)

My air pump puts out 950 GPH.


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## legallyflying (Aug 23, 2011)

tip top. yes, good point about the splitter and different pressures and flow rates affecting the results. HOWEVER, this is exactly the way that anyone that has a commercial pump uses them so in effect, your point is moot. I am testing real world results, not the DO rates given a specific air flow and pressure rate. I wanted to provide info for all, but mostly for those with larger set ups and commercial pumps. 

oh yeah man, the oxyponic system..forgot about those. They apparently can bend the laws of physics!!! LOL


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## RawBudzski (Aug 23, 2011)

My 1st grow was using the oxyponic system. 4x plants in an 18gal res. got about 5-6ft & yielded about 11oz under one 600w. I did not have a PH meter the entire grow. ^_^


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## tip top toker (Aug 23, 2011)

legallyflying said:


> tip top. yes, good point about the splitter and different pressures and flow rates affecting the results. HOWEVER, this is exactly the way that anyone that has a commercial pump uses them so in effect, your point is moot. I am testing real world results, not the DO rates given a specific air flow and pressure rate. I wanted to provide info for all, but mostly for those with larger set ups and commercial pumps.
> 
> oh yeah man, the oxyponic system..forgot about those. They apparently can bend the laws of physics!!! LOL


Surely in a commercial setup and such though, the airstones connected to the splitter would all be the same variety, not one of this and one of that, so that the pressure would be the same throughout, unlike in the test. It is not about given a specific pressure or rate, it is simply about if you attach X airstone to your pump, does it perform better than Y.


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## Mrfootball420 (Aug 23, 2011)

great work and i will definately not be buying the boss hog diffusers. but one thing i cant wrap my head around is how two stones can perform less then one? logically i dont see how that is possible.

nvm, i re read your post. it was on a single line. thats why.


thanks again


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## hellraizer30 (Aug 23, 2011)

awsome test legal rep to you sir


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## legallyflying (Aug 23, 2011)

RawBudzski said:


> My 1st grow was using the oxyponic system. 4x plants in an 18gal res. got about 5-6ft & yielded about 11oz under one 600w. I did not have a PH meter the entire grow. ^_^


Wow! 2.75 oz of of each plant for a grand total of .50 grams per watt? Dude, sign me up. Giggle.

Btw.. Your pump is only putting out around 60L/ min. 

Sorry man, I just had to. Let's keep things on topic


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## Mrfootball420 (Aug 23, 2011)

ok, i have had a little time to digest all of this and one thing of note is the 4in blue logicilly should not out perform the 6in. this leads me to believe the test is flawed. I believe the 4in blue was getting the proper amount of airflow so it was performing optimally while the 6in blue was not getting the level of air flow it required, and as a result the 6b had the lower DO.

i think a more accurate test would be testing one stone at a time with the exact same pressure. i also think you should use a larger tub or tote for the test, maybe like 20 gallons. i would imagine this would spread out the DO numbers from stone to stone quite a bit. right now they are all reading towards max levels and all of them are certainly capable of oxygenating 4-5 gallons. but my guess is a 6in is rated higher and therefore would add more DO to a larger space. 

i dont mean to rain on your parade bro and i thank you for all of your hard work, but i think the test is flawed. and i like you want answers, but i want the right answers, we all do.


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## newb19547 (Aug 23, 2011)

legallyflying said:


> Wow! 2.75 oz of of each plant for a grand total of .50 grams per watt? Dude, sign me up. Giggle.
> 
> Btw.. Your pump is only putting out around 60L/ min.
> 
> Sorry man, I just had to. Let's keep things on topic


You did see where he says he wasn't using a ph meter.....and who knows what else, right? lol.


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## BendBrewer (Aug 23, 2011)

But doesn't the OP state that he pretty much achieved maximum DO with all the stones? A 6" stone cannot work better than a 4" stone if the 4" stone reaches max DO.

I guess one could test how long each stone needs to reach max DO but does it matter as long as the stones provide O2 faster than the roots can absorb it?


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## hellraizer30 (Aug 23, 2011)

wondering what ph has to do with DO?


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## legallyflying (Aug 23, 2011)

Ummm, jump right in and tell me the test is flawed. Thanks bro. Let's get one thing straight, if a test isn't designed to test something YOU want, doesn't mean it's flawed. I tested the performance of different air stones at oxygenating bubble buckets using a commercial pump. I'm running dwc with 4 gallon buckets. 

I can't test all the different combinations of pumps and stones and different sized containers. The 4" stone did test below the 6" in 2 of the 3 temperatures. The one where it tested lower, it was .10 lower. That could be a slight diff in temp, meter float, anything really. 

I did the best I could given the materials I had. I am beginimg to think that other people don't do more tests like this because even if I had flow meters, pressure sensors, infrared thermometers and a gas chomatagraph to measure DO, there would still be someone that would throw out a nuh ugh. Or "the pressure is different, the test is null". As I said before, it DOESN'T MATTER that the pressure is different, maximum saturation was easily attained by even the cheapest stone. The pluses and minusus of some of the stones was discussed given their even performance. 

Maybe they do work differently with small pumps. Maybe there would be a difference if I threw them in a 50 gallon Rez. I didn't test that as I'm not using a standing 50 gallon Rez nor do I buy grow gear at PetCo. Maybe I'll do a head to head between two stones using a cheap two outlet pump. I'm certainly not going to fuck with 100's of gallons of water though.


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## Mrfootball420 (Aug 23, 2011)

BendBrewer said:


> But doesn't the OP state that he pretty much achieved maximum DO with all the stones? *A 6" stone cannot work better than a 4" stone if the 4" stone reaches max DO.
> *
> I guess one could test how long each stone needs to reach max DO but does it matter as long as the stones provide O2 faster than the roots can absorb it?






legallyflying said:


> ok,so I checked out DO maximums at a given temps ....http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm
> 
> There is no elevation given for those rates but in general, they track exactly with my measured results...
> 
> ...



thats exactly why the test is flawed. you could simply use bigger totes to show which stone actually produces the most DO based on pure volume. that would be the most accurate and easiest way imo. and not everyone is using 5 gallon buckets either. some are using multiple 18 gallon totes that carry volume over 100 gallons.

or you could test the water after every minite and monitor the gradual climb in the DO level to see which one hits maximum DO first knd of like you suggested but thats a lot more work.


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## legallyflying (Aug 23, 2011)

hellraizer30 said:


> wondering what ph has to do with DO?



Nothing at all. Apples and oranges.


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## BendBrewer (Aug 23, 2011)

Could you test the rate in which each stone creates max DO? Not that it would matter if they all do though.


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## Mrfootball420 (Aug 23, 2011)

legallyflying said:


> Ummm, jump right in and tell me the test is flawed. Thanks bro. Let's get one thing straight, if a test isn't designed to test something YOU want, doesn't mean it's flawed. I tested the performance of different air stones at oxygenating bubble buckets using a commercial pump. I'm running dwc with 4 gallon buckets.
> 
> I can't test all the different combinations of pumps and stones and different sized containers. The 4" stone did test below the 6" in 2 of the 3 temperatures. The one where it tested lower, it was .10 lower. That could be a slight diff in temp, meter float, anything really.
> 
> ...


no reason to get bent out of shape but the test if flawed. every stone you have is rated above oxygenating 4-5 gallons. did you think the stones didnt work? of course the were going to oxygenate that small amount of water if you let them run long enough. but how long did it take to accomplish that? which stone actually outperformed them all in creating maximum DO levels quickest? 

its just not an accurate measure for anything but a 5 gallon bucket rig and im sure those people really appreciate that(i know i do) but you certainly didnt "end the hype" imo. you just showed that for a small bucket you will reach max DO rates with just about any air stone and its a good test.

im sorry if i offended you in anyway and i again thank you for all of your hard work.


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## legallyflying (Aug 23, 2011)

Sorry if i take offense but if you had spent all night hunched over buckets, recording numbers, taking pictures, and then posting everything and have someone just come up and say. "its flawed". You would probably be a little defensive as well. Again, I wasn't trying to test big reservoirs. 

The point is that every stone is rated above oxygenating 4-5 gallons. therefore buying fancy stones or putting multiple stones in a bucket is a waste of money and energy. 

I would anticipate that using a commercial pump, any stone could also easily oxygenate a bigger reservoir. Thus the hype that you need a micro difuser or boss hog or any other expensive device is bunk. Your not talking that much of a volume increase from 5 to 18 or even 30 gallons. 

To prove this point I went down and measured my flower rez. There is about 30 gallons in there. I have a single 2" round airstone in there driven by one outlet of a whisper 100 pump. I don't know the rating on the whisper as it is not listed anywhere but it ain't much cause its only a 10 watt pump. and YES, the outlets are independent so it doesn't matter what stone is on the other end. 

76.5 degrees , 8.88 ml/l Tested three separate times, calibrating before each time. So there you go. A relatively cheap stone and a weak pump has achieved maximum saturation in 30 gallons. 

The test was as scientific as it needed to be. It's not my masters thesis. There are a myriad of variables you could account for but in the end, I don't feel it matters. I determined that the cheap stones are plenty to keep DO rates at their maximums. Therefore, I will never ever never think "hmm, I wonder if I would get better results if I used ________". 

Tell me you never thought "man, I wish I could afford those micro diffusers, those things look uber professional" I USED to think that.


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## BendBrewer (Aug 23, 2011)

I appreciate you demonstrating without a doubt that people buying those expensive stones are wasting their money.

I run a 1 stone per 3-4 gallons of solution. This test is perfect for me. Glad I didn't blow cash on the other stones.


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## legallyflying (Aug 23, 2011)

I was actually surprised that my 30 gallon rez is maxed out with the 2" round and cheesy pump. I was running two in there. Now I'll just keep the other line in my beneficial bucket.


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## Mrfootball420 (Aug 23, 2011)

legallyflying said:


> Sorry if i take offense but if you had spent all night hunched over buckets, recording numbers, taking pictures, and then posting everything and have someone just come up and say. "its flawed". You would probably be a little defensive as well. Again, I wasn't trying to test big reservoirs.
> 
> The point is that every stone is rated above oxygenating 4-5 gallons. therefore buying fancy stones or putting multiple stones in a bucket is a waste of money and energy.
> 
> ...


 
i have definately thought that, we all have.

i know you busted your ass on this test and i know it was a lot of hard work. and at first i wasnt going to comment but im sure glad i did now. as a result you went and checked your 30g rez and the results of that have added even more evidence to your test. i find it very comforting that your rez is is supporting max DO levels with such a small stone and pump, im sold.

thanks bro, excellent work....


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## legallyflying (Aug 23, 2011)

I love an online bromance. 

helllraizer, are you aware that if you like every single post that you read that when you actually do like a post...its utterly meaningless.


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## hellraizer30 (Aug 23, 2011)

lol yah legal was bored to shit and thought id like as many as I could


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## johnny garcia (Aug 23, 2011)

i always knew my 99 cent store 2 inch round airstone kicks 30 dollar stones butt


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## Rube Goldberg (Aug 23, 2011)

I often thought I should do a test like this! Great work! +rep


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## Mike Young (Aug 23, 2011)

Damn, I opened this thread this morning when there were only like 2 posts. Great test as far as I'm concerned. This shit is spensive enough already. Please someone talk me out of hortilux bulbs, lol.


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## legallyflying (Aug 23, 2011)

Cough...digilux.... Cough


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## Mike Young (Aug 23, 2011)

legallyflying said:


> Cough...digilux.... Cough


I can't really bitch, I only run one MH & one HPS. They treat me well, but I'd be lying if I said I wasn't curious as to how a $20 sylvania sized up.


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## tyler.durden (Aug 23, 2011)

Awesome test, LF! Thanks for busting your ass and sharing the results with us. I never would have thought that a 30 gallon rez would reach max DO with 10 watts, wtf? Love your sense of humor, even with the haters. Tried to +rep you again, but apparently I just did for something else, so it won't let me again so soon. I hate that shit, 'spread some rep around to some douche bags before giving it to someone who deserves it again'...


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## Mrfootball420 (Aug 23, 2011)

tyler.durden said:


> Awesome test, LF! Thanks for busting your ass and sharing the results with us. I never would have thought that a 30 gallon rez would reach max DO with 10 watts, wtf? Love your sense of humor, even with the haters. Tried to +rep you again, but apparently I just did for something else, so it won't let me again so soon. I hate that shit, 'spread some rep around to some douche bags before giving it to someone who deserves it again'...



without the so called hater you wouldnt have known that a 30g rez could reach max DO with a 10w pump and a 2in airstone.... your welcome!!!


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## tyler.durden (Aug 24, 2011)

Mrfootball420 said:


> without the so called hater you wouldnt have known that a 30g rez could reach max DO with a 10w pump and a 2in airstone.... your welcome!!!


Good point, but I wasn't referring to you specifically, plenty of other guys hate on this dude


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## Heisenberg (Aug 24, 2011)

Excellent work and report, thank you!


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## legallyflying (Aug 24, 2011)

Yo Heisenbuerg, you have any idea or data on what oxygen uptake rates are for mature plants? Also, will the plants actually absorb oxygen via contact with bubbles. Obviously DO levels are important but my thought is that perhaps the presence of bubbles actually matters. 

The reason I say this is that A. there is no oxygen in solution in soil and B. people have experienced better results through placing more airstones in their containers. Or at least that is what they attributed the difference to.

Thanks,
LF


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## Heisenberg (Aug 24, 2011)

legallyflying said:


> Yo Heisenbuerg, you have any idea or data on what oxygen uptake rates are for mature plants? Also, will the plants actually absorb oxygen via contact with bubbles. Obviously DO levels are important but my thought is that perhaps the presence of bubbles actually matters.
> 
> The reason I say this is that A. there is no oxygen in solution in soil and B. people have experienced better results through placing more airstones in their containers. Or at least that is what they attributed the difference to.
> 
> ...


The real reason to pay attention to DO levels is to prevent pathogens from growing. Pathogens have a hard time living in any solution aerated to 6pp-8pp DO. Going above 8ppm is redundant in this context. 

At 8ppm DO you are only supplying about 1% of what the roots require, the rest has to come from contact with air. The more oxygen available, the more oxidization can take place which allows more photosynthesis up top. That is why more bubbles equals better performance, and why aeroponic systems have wild growth. More oxygen = more feeding = more energy for photosynthesis = more growth. Studies have shown roots can spend only 1 sec of every minute in direct contact with (atomized) nute solution and plants still grow at amazing rates. When you consider this, the difference between 8ppm and 10ppm DO in the water seems negligible, and the importance of well placed stones becomes apparent. 

http://en.wikipedia.org/wiki/Aeroponics
http://hydroponics-gardening-information.com/Oxygen.html


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## legallyflying (Aug 24, 2011)

Well there you have it. I kind of suspected that it was not just do. I work as wetland biologist and even the most saturated soils will not support plants that do not possess adaptations to thrive in anerobic soil conditions. 

What kind of pump stone set up are you using currently?


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## hydrohomer (Aug 24, 2011)

Hey legallyflying... great test and quite enjoying the ensuing discussion.

For shits and giggles, why not try one without an airstone? Just sink an open airline and see what that's all about. Just an idea, an maybe a valuable indicator that airstones actually do something!

Thanks again, great info +rep


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## Heisenberg (Aug 25, 2011)

legallyflying said:


> What kind of pump stone set up are you using currently?


I currently use a 35wt compressor to run 6-8 buckets, I use two 4inch blue stones in each bucket, and I leave at least an inch of air gap at the bottoms of the net cups so the roots can breath.


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## legallyflying (Aug 25, 2011)

Interesting. One observation I made during the airstone test of the blue stones is that the 4" and the 6" seemed to disrupt the water equally or at least as close to equal as I can discern with the naked eye. Perhaps the 6" moved a little more water. However, while taking pictures of the stones with my underwater camera, the 6" seem to be putting off more actual "air stone" sized bubbles. It was almost as if the high pressure and smaller stone combo caused many more bigger bubbles to form. As if the pump was simply over sized for the smaller stone. 

You make an excellent point however about DO rates and free oxygen amounts. It seems that for the ebb/flow crowd or those mixing large batches of soil water, a cheap pump and cheap stone is more than enough to reach full DO rates. There is absolutely no reason to be spending money on expensive diffusers or multiple stones in a rez. 

For those that are growing with plants immersed in water, it is pretty obvious that free air levels are key as this is what plants need and any stone is going to easily surpass maximum DO pretty quickly. 

To that end, I was thinking about the diffuser -vs- regular air stones. The diffuser puts out lots of bubbles, but becuase the pore size is so small, it clearly passes less air through it. So the discussion then turns to which approach lends itself to more oxygen/root interface time or...which approach achieves the most oxygen surface area-- smaller bubbles, but less of them or bigger bubbles. If you took the same quantity of air and made bubbles out of them then the smaller bubbles would have more surface area collectively. However, that is not the case in the diffuser-regular stone decision as the diffuser is clearly allowing much less air to pass through it based on naked eye observations. 

I may be biased towards the regular stones because the diffusers are sooo expensive. But I feel that all things being equal, the 6" blue stone or 2" round is more applicable to DWC simply because of thee ease at which it allows air to pass through it. As for one or two stones per DWC bucket, I'm still on the fence. There is the advantage of having two stones in that if one becomes clogged you have a back up so to speak. The other side of the equation is that two stones, when reaching the end of a growth cycle and the buckets are absolutely full of roots, would more evenly distribute the bubbles through the root zone. 

Any thoughts?


----------



## BendBrewer (Aug 25, 2011)

Heisenberg said:


> At 8ppm DO you are only supplying about 1% of what the roots require, the rest has to come from contact with air. The more oxygen available, the more oxidization can take place which allows more photosynthesis up top.


Do the air stones increase the density of O2 in the airspace inside the bucket? Would different stones supply more or less O2 to this space? Does the concentration or percentage of O2 in this airspace even matter?


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## kannibis (Aug 25, 2011)

Has anyone ever tried using pure o2 as a feed for the stones?


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## BendBrewer (Aug 25, 2011)

kannibis said:


> Has anyone ever tried using pure o2 as a feed for the stones?


That would be hella spendy.


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## kannibis (Aug 25, 2011)

Not really. An oxygen generator, such as the ones used for people with COPD. I would think it would supply more than the standard atmospheric amounts. But I'm curious if the effect would be worth the time and effort....


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## r1tony (Sep 15, 2011)

Late to the party but good read OP +rep


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## legallyflying (Sep 15, 2011)

fuck. just typed huge repply and log in timed out. Have to do it later.


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## panhead (Sep 15, 2011)

BendBrewer said:


> I appreciate you demonstrating without a doubt that people buying those expensive stones are wasting their money.
> 
> I run a 1 stone per 3-4 gallons of solution. This test is perfect for me. Glad I didn't blow cash on the other stones.


I agree,unless somebody is running a monster rez over 100 gallons this test is perfect,my rez's are 50 gal & the test backed up what i allreadt guessed.

I rarely leave rep but this is one instance.

Great job man,dont let the negative bullshit get ya down,most of the time all the negative nancy types are just trying to show their knowledge on the subject & whats the fastest way to show yer smart,dissagree with something then search for flaws.

Its marijuana growing guys not rocket sceince,everything is flawed but this is one kick ass bit of info.


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## legallyflying (Sep 15, 2011)

Thanks man. Appreciate it allot. For everyone except those running dwc the test answers allot of questions. For dwc however, as heisenburgs contribution confirmed to me.. That while max DO rates are easy to achieve, DWC needs quite a bit more "free air" as the bubbles Interfacing with the roots provides them with oxygen. So in this respect the micro bubbles MAY be better but they certainly cause a large reduction on flow because of pore size. 

They also clog rather quickly in organic or bene filled dwc. For this reason, the choice for me was push lots of air through cheap porous stones that resist clogging. At the end of each grow.. Throw them away and start fresh


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## legallyflying (Sep 15, 2011)

Thanks man. Appreciate it allot. For everyone except those running dwc the test answers allot of questions. For dwc however, as heisenburgs contribution confirmed to me.. That while max DO rates are easy to achieve, DWC needs quite a bit more "free air" as the bubbles Interfacing with the roots provides them with oxygen. So in this respect the micro bubbles MAY be better but they certainly cause a large reduction on flow because of pore size. 

They also clog rather quickly in organic or bene filled dwc. For this reason, the choice for me was push lots of air through cheap porous stones that resist clogging. At the end of each grow.. Throw them away and start fresh


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## hellraizer30 (Sep 15, 2011)

hey legal thanks for your time in these DIY and test you have post I know people have disrespect sometime but theres alot of us that feel its all positive thanks legal


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## rzza (Sep 16, 2011)

i use the four ft diffusers and every morning i wake up and there are NO bubbles. just standing water. so i lift them out of the water and clean em up and then i get little bubbles. i want lots of buubbles. 

why not just turn on the air pump and stick the hoses right in the water? that looks like its giving great bubbles. also i dont wake up to clogged diffuser. what do i do?


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## legallyflying (Sep 16, 2011)

Need more info. Pump type/output and is this in a Rez or dwc bucket? 

I would buy a $1.25 6" blue airstone and be done with it. I'm currently using my 3' bubble line as a twistie tie on my mother plant. You probably could just use no stone but the blue stOne will increase DO rates and provide more mixing.


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## rzza (Sep 16, 2011)

its a tote i built for cloneing/veg. it holds 18 3 inch nets. 4 watt dual fitting air pump. $14.95 at an overpriced hydroshop.


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## legallyflying (Sep 16, 2011)

That only puts put around 4 liters a minute which is fine I guess. I would still say pick up some airstones. 

BUT! Remember that you can use roots excelerator or any other rooting wonder agent that comes in a metal bottle with an airstone. The anaerobic bacteria in the rooting agent will gunk up..well everything really. This is another solution that adresses why you have gunk in your cloner. It's a big no no. The root excelerator is not for dwc or any situation where you need airstones 

Are you using it?


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## rzza (Sep 16, 2011)

the only solutions i used were general hydroponic 3 part formula and 1.5 tsp of peroxide.

i just bought 2 6 inch blue stones.


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## rzza (Sep 16, 2011)

i should mention im switching from dirt and im brand new with water.


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## legallyflying (Sep 16, 2011)

Well welcome to the hydro game. Are you going to use DWC? If so, be sure to visit the brew our own tea thread (slime cure). Your going to shit yourself at how fast plants grow in dwc. It's normal until about week 3 then it just explodes!! ITs pretty fucking awesome really.


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## rzza (Sep 16, 2011)

Thanks, i'm growing undercurrent/vertical. similar to this guy...

http://www.thcfarmer.com/forums/f158/60-x-1000-watts-under-current-hydro-20-tons-ac-some-co2-19366/


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## rzza (Sep 16, 2011)

but the veg is a simple 18 pot tote, bubbler.


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## hellraizer30 (Sep 16, 2011)

welcome to the hydro world!


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## rzza (Sep 16, 2011)

Thanks hr30. I switched cause I cant get a dirt plant taller than 5 inches in 4 weeks.


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## legallyflying (Sep 16, 2011)

rzza said:


> Thanks hr30. I switched cause I cant get a dirt plant taller than 5 inches in 4 weeks.


shit man, I can grow a clone almost three feet in 4 weeks.


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## hellraizer30 (Sep 16, 2011)

legallyflying said:


> shit man, I can grow a clone almost three feet in 4 weeks.


kinda what I was thinking


----------



## rzza (Sep 16, 2011)

legallyflying said:


> shit man, I can grow a clone almost three feet in 4 weeks.


exactly lOl


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## woodsmaneh! (Sep 25, 2011)

great report, that's how we make progress. I buy 8" blue stones by the box, 24 in a box and pay 15$ a box. Use them and toss, I do use a 9" pond defuser with 6,600 holes in it and it is low pressure, here is a pic. In my new 200 gal system I have a 280 w air pump with 9 8" air stones and 1 9" defuser. I run chillers and keep temps at 62 to 63 for max DO and to keep the bad guys at bay. The foam is from DM Zone it does that because the defuser puts out a ton of very small bubbles.

FishFarmSupply > Aeration > Air Diffuser 

*Flexair Fine Bubble Disc Diffuser - 9''*


*Quantity in Basket: *

_None_ 
*Product Code: *

ED327 
*Price:  $32.83 *


*Shipping Weight: *

3.00 pounds 

*Quantity: *




[FONT=Arial, Helvetica][SIZE=-1]Promotion Code: 

FlexAir&#8482; disc diffuser bodies are made of high strength polypropylene with 3/4 &#8221; MNPT connections. Each diffuser has a minimum of 6,600 engineered air release orifices, which is up to 20 percent more than comparable models. The special design of the EPDM membrane, with its engineered thickness taper, results in full utilization of the membrane surface, even at low airflow operations. This results in improved oxygen transfer efficiency, along with maximum operational flexibility. The disc diffuser has an integral &#8220;triple&#8221; check valve to prevent fluid back flow. Normal airflow range is 0 to 5 cfm. Resistance is about 10&#8221; H2O when clean. FlexAir&#8482; disc diffusers in stock have fine bubble EPDM membranes installed and weighs 2 lbs. Made in USA. 




, 
[/SIZE][/FONT]

View attachment 1806375View attachment 1806376View attachment 1806377View attachment 1806378


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## woodsmaneh! (Sep 25, 2011)

*[FONT=&quot]Higher dissolved oxygen great for productivity, health and vigor

[/FONT] [FONT=&quot]Research[/FONT][FONT=&quot] > [/FONT][FONT=&quot]Learn About Research[/FONT][FONT=&quot] > [/FONT][FONT=&quot]News[/FONT][FONT=&quot] > Higher dissolved oxygen great for productivity, health and vigor [/FONT]
[FONT=&quot]By Robert Fieldhouse 
(Guelph, October 13, 2005)

[/FONT] [FONT=&quot]Dissolving more oxygen into hydroponic solutions could boost greenhouse productivity and provide a whole host of other benefits too, say University of Guelph researchers.[/FONT]
[FONT=&quot]Prof. Mike Dixon and Dr. Youbin Zheng, Department of Environmental Biology, are investigating the positive aspects of using an oxygen diffuser to increase oxygen levels in greenhouse hydroponic solutions used to grow roses, tomatoes, cucumbers and peppers. [/FONT]
[FONT=&quot]




[/FONT]
[FONT=&quot]Dr. Youbin Zheng, Department of Environmental Biology, is studying if oxygen levels can be boosted in hydroponic solutions to help growers ward off harmful microbes and boost productivity. [/FONT]

[FONT=&quot]Preliminary results suggest a higher dissolved oxygen level increase productivity, health and root vigor in greenhouse plants, and helps keep harmful microbes in check.[/FONT]
[FONT=&quot]&#8220;These findings are really beneficial to the industry,&#8221; says Zheng. &#8220;If we can use oxygen to boost plant health, making them stronger and more resistant to disease, we've discovered a very helpful tool.&#8221;[/FONT]
[FONT=&quot]Oxygen isn't as prevalent in warm water as in cool water, so oxygen levels tend to be low -- about two to four parts per million (ppm) -- at high greenhouse temperatures, compared to eight to nine ppm in cool water. Under hot weather in the greenhouse, the root zone is especially short on oxygen, says Zheng, because root respiration depletes oxygen in hydroponic solutions. Excessive watering can further depress oxygen levels because it makes growth media, such as rockwool or coconut fibre, less porous, blocking air. These factors all weaken plant disease defense systems, making them more susceptible to disease-causing microbes such as Fusarium and Pythium which cause root decay.[/FONT]
[FONT=&quot]To prevent this problem, greenhouse growers typically bubble air into hydroponic solutions to bring oxygen levels up to about nine ppm. But sometimes this still isn't enough.[/FONT]
[FONT=&quot]Two years ago, the BC Greenhouse Growers' Association asked Dixon to investigate using even higher oxygen levels in hydroponic solutions. His literature review revealed that very little work had been done in this area suggesting the problem was largely ignored &#8211; until now.[/FONT]
[FONT=&quot]Dixon and Zheng are using an oxygen diffuser recently developed and manufactured by Seair Diffusion Systems Inc., an Edmonton-based company with an interest in the greenhouse sector. The diffuser concentrates atmospheric oxygen, and dissolves it into hydroponic solutions. With this technology, oxygen levels can reach as high as 60 ppm in hydroponic solutions.[/FONT]
[FONT=&quot]The research team is currently studying the effects of different oxygen levels, ranging from about nine ppm to 40 ppm.[/FONT]
[FONT=&quot]So far, preliminary results are promising. But creating optimal supersaturated oxygen solutions requires extreme precision. Oxygen can be damaging at very high levels, says Dixon , so it's important to establish application methods for using this technology for different crops.[/FONT]
[FONT=&quot]But if the methods can be worked out, Dixon says the oxygen diffusers are inexpensive and stand to emerge as an economical, environmentally friendly solution for growers looking to enhance their crops.[/FONT]
[FONT=&quot]&#8220;Greenhouse growers are voracious technical consumers &#8211; they'll try anything,&#8221; says Dixon . &#8220;But by the same token, they're also very shrewd business people, and they won't waste money unnecessarily.&#8221;[/FONT]
[FONT=&quot]Dixon and Zheng will continue their research and will further investigate oxygen's effect on plant growth, physiology and disease. For example, they will inoculate greenhouse plants with specific microbes to see how the plants cope with this challenge under different oxygen levels.[/FONT]
[FONT=&quot]Other researchers involved in this project include technician Linping Wang, graduate student Johanna Valentine and undergraduate student Mark Mallany, Department of Environmental Biology.[/FONT]
[FONT=&quot]This research is being conducted at greenhouses in Guelph and Leamington , Ontario . It is sponsored by Seair Diffusion Systems Inc., Flowers Canada Ontario and the Fred Miller Rose Research Fund.[/FONT]*


----------



## legallyflying (Sep 26, 2011)

Hey woodsman. So your not seeing issues with that cold of water? I recently started a fresh Rez (800 ppm) and lowered temps to around 63. I got allot of non burning rams horns. Did a little reading and found most temp recommendations in the 68 range. I backed off the chilling and the problem went away. At the same time however, my ppm dropped to 650 or so I can't definitively point the finger at temps . 

Could be strain dependent?


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## lordjin (Sep 26, 2011)

Very informative. Ultra-geeky.


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## Oldgrowth (Oct 21, 2011)

Mrfootball420 said:


> no reason to get bent out of shape but the test if flawed. every stone you have is rated above oxygenating 4-5 gallons. did you think the stones didnt work? of course the were going to oxygenate that small amount of water if you let them run long enough. but how long did it take to accomplish that? which stone actually outperformed them all in creating maximum DO levels quickest?
> 
> its just not an accurate measure for anything but a 5 gallon bucket rig and im sure those people really appreciate that(i know i do) but you certainly didnt "end the hype" imo. you just showed that for a small bucket you will reach max DO rates with just about any air stone and its a good test.
> 
> im sorry if i offended you in anyway and i again thank you for all of your hard work.


Ive got a great idea! Why dont you run the test on large res for the rest of us instead of putting down all the work he did. then we can find somthing in your test that makes it not valid to us?


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## hellraizer30 (Oct 21, 2011)

I run my water at 61 to 62f without issues


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## Mindmelted (Oct 28, 2011)

I have used the same micro air difusser for 2 years.So your cost is way off base as you do not need to replace them.


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## legallyflying (Oct 28, 2011)

You want to buy mine? 

I'm actually pretty dead set against them for a couple reasons. 

Cost is big.. 18 sites x $20= $360!!
You can't use just a couple of them on a splitter. They are really tight and air will flow to other more porous stones 
They make the pump work harder
There is less air flow, yes the bubbles are smaller but overall, compared to the sheer number of bubbles coming off the blue stones it's really close. 
The biggest reason..in a 40 gallon res, one 4" blue stone was able to provide max DO

They are high quality and very though. Not going to break them and reusing then is a plus. I think if you just need a couple might be a good investment. I need a total of 42 stones though for 18 site veg room and 12 site flower (With 2 stones each) . Thats more than $800 for a one time investment. That's equal to replacing the blue stones 20 times...which is 5 years worth of grows. I probably won't be growing in 5 years. 

But anywho, many ways to skin a horse.


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## legallyflying (Nov 8, 2011)

Thought I would drop in on this thread and drop a little observation. While I think I was able to show that it's pretty easy to hit max DO with any little pump, I have to say that in a DWC setup, really overdoing the amount of air yields great results! While many will say the startibg point is 1 watt per gallon of water, I recently ran 4 liters per minute per gallon in my early veg tote and the plants really exploded. The water was a frothing monster but the plants absolutely loved it! 

So for those starting a DWC system, I would really advise spending the little extra coin and getting a BIG pump. 
Cheers


----------



## BeaverHuntr (Nov 8, 2011)

legallyflying said:


> Thought I would drop in on this thread and drop a little observation. While I think I was able to show that it's pretty easy to hit max DO with any little pump, I have to say that in a DWC setup, really overdoing the amount of air yields great results! While many will say the startibg point is 1 watt per gallon of water, I recently ran 4 liters per minute per gallon in my early veg tote and the plants really exploded. The water was a frothing monster but the plants absolutely loved it!
> 
> So for those starting a DWC system, I would really advise spending the little extra coin and getting a BIG pump.
> 
> Cheers


Yes it does. I cant even begin to tell you how big my rootball would get because I would blast some buckets with 3 air stones and some with 4.. I would literally get waves in my buckets but the plants were huge.


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## legallyflying (Nov 8, 2011)

Word. I was using a 110 L/M pump to aerate 12 4 gallon buckets (with 3 gallons of water in each). Which is basically 3 liters per gallon of water/ minute. I added another 110L pump in order to have a failsafe backup and double airflow. The plants really like it.


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## woodsmaneh! (Nov 8, 2011)

Yup the great thing about using an air pump and stone setup is you can not over oxygenate the water. As a side note to much DO will kill a plant but to do that you need about 15,000$ worth of equipment. The University of Gulph in Canada has a research paper on it. I like using the 9" EPDM pond aerators. Low pressure to boot, never clogs a bizillon tiny bubbles.

[FONT=Arial, Helvetica][SIZE=-1]FlexAir disc diffuser bodies are made of high strength polypropylene with 3/4  MNPT connections. Each diffuser has a minimum of 6,600 engineered air release orifices, which is up to 20 percent more than comparable models. The special design of the EPDM membrane, with its engineered thickness taper, results in full utilization of the membrane surface, even at low airflow operations. This results in improved oxygen transfer efficiency, along with maximum operational flexibility. The disc diffuser has an integral triple check valve to prevent fluid back flow. Normal airflow range is 0 to 5 cfm. Resistance is about 10 H2O when clean. FlexAir disc diffusers in stock have fine bubble EPDM membranes installed and weighs 2 lbs. Made in USA. 




[/SIZE][/FONT]


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## Big P (Jan 13, 2012)

woodsmaneh! said:


> Yup the great thing about using an air pump and stone setup is you can not over oxygenate the water. As a side note to much DO will kill a plant but to do that you need about 15,000$ worth of equipment. The University of Gulph in Canada has a research paper on it. I like using the 9" EPDM pond aerators. Low pressure to boot, never clogs a bizillon tiny bubbles.
> 
> [SIZE=-1]FlexAir&#8482; disc diffuser bodies are made of high strength polypropylene with 3/4 &#8221; MNPT connections. Each diffuser has a minimum of 6,600 engineered air release orifices, which is up to 20 percent more than comparable models. The special design of the EPDM membrane, with its engineered thickness taper, results in full utilization of the membrane surface, even at low airflow operations. This results in improved oxygen transfer efficiency, along with maximum operational flexibility. The disc diffuser has an integral &#8220;triple&#8221; check valve to prevent fluid back flow. Normal airflow range is 0 to 5 cfm. Resistance is about 10&#8221; H2O when clean. FlexAir&#8482; disc diffusers in stock have fine bubble EPDM membranes installed and weighs 2 lbs. Made in USA.
> 
> ...



Sup man, how long have you had that [SIZE=-1]FlexAir&#8482; disc diffuser[/SIZE]. Are you sure it cant clog? im looking for one that never clogs, im so tired of clogged air stones. I was about to get this one below but I came across this one , so Ill wait till i get your review on how long youve been using it for & if its clog proof & if you recommend it still

thanks


Word seems to be that this one will never clog cuz its silicon and expands a little to let the air out:


*Silicone Rubber Diffuser Hose *












*Application:*

Aquaculture aeration
*Features and Benefits:*

Durable, lightweight, resilient silicone rubber
Resistant to low/high pH, corrosion, crack or burst
Light to moderate ozone resistance
Easy to install, reshape, reposition, remove and storage
Can be laid to form variety of patterns, allowing high coverage area with 
long hose length
Designed for even distribution of air bubbles along the entire hose 
length
High oxygen transfer
Resistant to clog and with self cleaning ability
Low pressure loss
Low air pump power requirement
Suitable for intermittent or continuous duty application
Back flow resistant
Offer years of durable and clog free service compare to traditional black 
rubber hose
*Specification:*
Hose size: 11mm ID, 14mm OD
Minimum curve radius: ~8 cm, ~3 
in
Applicable length: 0.1 ~ 30+ meter, 4 in ~ 100+ ft​*Example:*




​General Installation Guide


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## woodsmaneh! (Jan 13, 2012)

Big P said:


> Sup man, how long have you had that [SIZE=-1]FlexAir&#8482; disc diffuser[/SIZE]. Are you sure it cant clog? im looking for one that never clogs, im so tired of clogged air stones. I was about to get this one below but I came across this one , so Ill wait till i get your review on how long youve been using it for & if its clog proof & if you recommend it still
> 
> thanks
> 
> ...


I have had one for over a year and these do not clog, the membrain is rubber and inflates when you put air to it. When you shut it off it shrinks back to origanal size. I bought another about 6 months ago and love them. I found a place that amkes them and they sell for $16 each I will be replacing all my stones with this. See my next post.


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## woodsmaneh! (Jan 13, 2012)

Well did some research into air stones and was not to happy with what I found. The blue stones, I still use them but am phasing them out, are the worst to use due to the bubble size they produce. 

First thing is the smaller the bubble the better, the blue one have 5000+ micron bubbles but as soon as they get dirty/cloged they can go to 8000 to 10000 microns. The oxygen shields are 3000 microns which is great...

http://www.deepwaterinnovations.com/Products/OxygenShieldAirDiffuser.aspx

The Disk I use comes in 2 hole sizes, small and med., I use the small as the bubbles it produces are .500 microns and way better for roots.

http://www.pollardwater.com/pages_product/WED01691EDIFlexAirDiskDiffuser.asp


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## legallyflying (Jan 13, 2012)

I'm glad to see this thread re-surfacing. Again, I feel there is a trade off between really small bubbles..like the REALLY expensive micro pore stones that offer too much resistance to flow (IMO) and the cheap ass blue stones that clog 

I'm ditching the blue stones for sure. I have been looking at the alita stones which I have heard can NOT clog, ever, period, and the disks. What is nice about the discs and the alita airtones as they come with 1/2 threaded fittings so you can hard pipe them into your tank for much greater flow of air. 

How do those discs work for you? Are the bubbles small enough? Looking at their website and info, my 110 lpm pump will be able to drive 4 of them at slightly above their design flow but still WAY below their maximum. They do seem like more bang for the buck compared to the DWI oxygen shield.. which seems like something thrown together to sell to growers. 

AT any rate, a significant investment but may be worth while.


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## mike91sr (Jan 13, 2012)

The reason I still like the 4" blue stones is I feel like the extra water turbulence I notice over other stones will help penetrate a thick root system. Legit concern or just retarded over-analyzing?


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## woodsmaneh! (Jan 13, 2012)

mike91sr said:


> The reason I still like the 4" blue stones is I feel like the extra water turbulence I notice over other stones will help penetrate a thick root system. Legit concern or just retarded over-analyzing?


We would need to compair apples to apples, you also need a air pump that can push the stone. The more air the better, the more air (smaller bubbles) the better.

If you want to max your blue stone use an "o"ring on each end to keep it off the bottom.

http://www.fishfarmsupply.ca/mm5/merchant.mvc?Screen=PROD&Store_Code=FFS&Product_Code=DB10&Category_Code=airDiff

now if your compairing the 4" blue stone to the 9" FlexAir stay on the porch with the little dogs.


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## woodsmaneh! (Jan 13, 2012)

I'm voteing with my money 9" FlexAir is the dope


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## mike91sr (Jan 13, 2012)

I wasn't comparing to a stone that costs 20x as much, no. I was comparing to the other common stones on the same pump, though not specifically that one. Even still, I stand by the fact that, on the same pump, it won't be any better. Legally's test proved that 2x6" is worse than 1x6". So on a pump realistically sized for most setups, same problem with your stone. Unless I wanted to use my 112w commercial pump to only run one or two stones instead of the 12 I need, then I could just buy 5 more pumps and obviously that means more air too, but that doesn't always mean it's an efficient or viable option.


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## Huel Perkins (Jan 14, 2012)

Great thread Legallyflying!

I personally would love to see some testing done to see how H2O2 (hydrogen peroxide) effect the DO levels in water. I myself grow in DWC and use 3ml of 29% H2O2 in every gallon of water that goes into my entire grow. I have always wondered the effects this has on the actual DO levels as well as how long the H2O2 actually keeps the DO levels elevated before it evaporates off. Maybe you could do some H2O2 testing.


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## woodsmaneh! (Jan 14, 2012)

I don't mess with pumps, I just buy big ones, 180 and 280 watt linear air pumps. I even run a 180 for my cloner and it will drive 8 6" air stones no problem. I use to run 6 or 8 small pumps but it was a pain for me.

If your comparing blue stones to ceramic or high density stones blue are at the bottom. Don't get me wrong they work good but I am always trying to get a little more out of my grows so I do a lot of testing.

Legal has done a great job, I'm just adding my 2 cents worth.

Peace

The way to get higher sustained DO is lots of small bubbles and lower temps, 62 degrees.


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## woodsmaneh! (Jan 14, 2012)

mike91sr said:


> I wasn't comparing to a stone that costs 20x as much, no. I was comparing to the other common stones on the same pump, though not specifically that one. Even still, I stand by the fact that, on the same pump, it won't be any better. Legally's test proved that 2x6" is worse than 1x6". So on a pump realistically sized for most setups, same problem with your stone. Unless I wanted to use my 112w commercial pump to only run one or two stones instead of the 12 I need, then I could just buy 5 more pumps and obviously that means more air too, but that doesn't always mean it's an efficient or viable option.


I don't agree, if you take a 1" blue and a 1" ceramic on the same pump it will out perform the blue hands down. The size of the bubbles and quantity of bubbles is far better with the ceramic than the blue. IMHO

Just put the 2 side by side and you will see a difference.

The issue is more about money than anything else in my opinion, most people who grow are just cheap, there is no tomorrow for them. I see it all the time in the hydro stores when people come in and buy the least expensive equipment. Yes some can't afford to spend much, but most don't want to. As I have always said you can buy the hay before the cow eats it or after.

I am always looking for a better way, that's how progress is made, also by failing you learn and make progress LOL


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## woodsmaneh! (Jan 14, 2012)

Just want to point out you want to size the air stone on the finished size of root system. As the roots grow you need more and more bubbles to do the same job, here is some more info

Injury from low (or no) oxygen in the root zone can take several forms and these will differ in severity between plant types. Often the first sign of inadequate oxygen supply to the roots is wilting of the plant under warm conditions and high light levels. Insufficient oxygen reduces the permeability of the roots to water and there will be an accumulation of toxins, so that both water and minerals are not absorbed in sufficient amounts to support plant growth. This wilting is accompanied by slower rates of photosynthesis and carbohydrate transfer, so that over time, plant growth is reduced and yields are affected. If oxygen starvation continues, mineral deficiencies will begin to show, roots die back and plants will become stunted. If the lack of oxygen continues in the root zone, plants produce a stress hormone - ethylene, which accumulates in the roots and causes collapse of the root cells, at this stage pathogens such as pythium can easily take hold and destroy the plant. 

While an air pump tube alone can bubble air into a nutrient solution, oxygenation or the process of getting atmospheric oxygen dissolved into the liquid nutrient, is much more effective where many tiny bubbles of air are created, rather than a slow stream of larger bubbles.* The greater the surface contact between the air bubbles and the nutrient, the more oxygen will diffuse into the nutrient solution and smaller bubbles create a far greater surface area than a few larger bubbles will*. The further the bubbles have to travel to reach the surface of the nutrient, the more time oxygen has to diffuse into the liquid and the higher the rates of dissolved oxygen than can be obtained from an air pump and stone set up. 
*
Oxygen and Temperature Effects - Effective Aeration*

While forcing air bubbles deep down into the nutrient reservoir generally increases the dissolved oxygen levels in the nutrient, there is one other major factor to consider and that's the temperature of the air being pumped into the nutrient. As the temperature of a nutrient solution increases, its ability to hold dissolved oxygen decreases. So a cool nutrient solution may in fact hold twice as much oxygen at 'saturation level' than a warm solution. For example a nutrient solution at 45 F can hold around 12ppm of dissolved oxygen at 'saturation', (meaning it is the most it can hold), but the same nutrient solution at a temperature of 85 F will hold less than 7ppm at saturation. This means at a solution temperature of 85F there is much less dissolved oxygen available for the plants root system to take up. To complicate matters further, the requirement of the plants root system for oxygen at warmer temperatures, is many times greater than at cooler temperatures due to the increased rate of root respiration. So warm nutrients mean a very high oxygen requirement from the plants roots, but the nutrient can only hold very limited amounts of dissolved oxygen at saturation, no matter how much air is being bubbled into the solution. Ideally, nutrient solution temperatures for most plants should be run lower than the overall air temperature - this has many beneficial effects on plant growth and development. However, if overly warm air from the growing environment is pumped into an otherwise cool nutrient solution, the warm air will rapidly increase the temperature of the nutrient to that of the growing environment. If air is being pumped via an air machine with an intake close to lights or other heat sources then rapid heating of the nutrient will occur. On the other hand, cool air has the ability to reduce the temperature of the nutrient if sufficient levels are pumped in and thus result in a much more highly oxygenated solution for the plants roots. If keeping the nutrient solution temperature down seems to be a continual problem, checking the air inlet temperature of an air pump is a good idea. Overly warm nutrient solutions (ideally nutrient solutions should remain below 65 - 75 F) for most warm season, high light plants and well below 69 F for cool season.can have serious effects on the plants root system. Apart from the increased oxygen requirement due to a much higher rate of root respiration which can rapidly result in oxygen starvation, high solution temperatures favour many of the root disease pathogens. Plant roots become highly 'stressed' when experiencing high temperatures, particularly if there is a large mis-match between the air the root temperature. Root stress slows the development of new roots, resulting in reserves inside the root tissue being `burned up during respiration faster than they are accumulated, and stress makes the root system in general more susceptible to disease attack. Keeping a check on nutrient temperature is vital, as is ensuring that air machines are not blasting hot air into the solution and cooking plant roots. Aeration is most effective when cool air is bubbled into a nutrient. 
*
Oxygenation and Nutrient Uptake*

Healthy roots supplied with sufficient oxygen are able to absorb nutrient ions selectively from the surrounding solution as required. The metabolic energy which is required to drive this nutrient uptake process is obtained from root respiration using oxygen. In fact there can be a net loss of nutrient ions from a plants root system when suffering from a lack of oxygen (anaerobic conditions). Without sufficient oxygen in the root zone, plants are unable to take up mineral nutrients in the concentrations required for maximum growth and development. Maintain maximum levels of dissolved oxygen boosts nutrient uptake by ensuring healthy roots have the energy required to rapidly take up and transport water and mineral ions. Calcium is one important nutrient ion which has been shown to benefit from high levels of oxygenation in the hydroponic nutrient solution Calcium, unlike the other major nutrients is absorbed mostly by the root growing tips (root apex). The root apex has a large energy requirement for new cell production and growth and is therefore vulnerable to oxygen stress If root tips begin to suffer from a lack of oxygen, a shortage of calcium in the shoot will occur. This shortage of calcium makes the development of calcium disorders such as tip burn and blossom end rot of fruit more likely and severe under oxygen starvation conditions. High levels of oxygenation ensure healthy root tips are able to take the levels of calcium required for new tissue growth and development. 
*
Conclusion*

While providing oxygenation with the use of air pumps and stones is an excellent method of increasing the dissolved oxygen (DO) levels in a nutrient solution, the temperature of the air intake and nutrient solution must also be managed to ensure oxygen starvation in the root zone does not occur. *Pumping hot air into a nutrient not only creates temperature stress in the root zone, it also results in less oxygen carrying capacity in the solution itself - a recipe for root suffocation that will rapidly affect the top portion of the plant as well. *Getting oxygenation right means checking both aeration capacity of the equipment being chosen and temperatures in the nutrient and root zone.


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## legallyflying (Jan 14, 2012)

I'm with woodsman on this one and I am going to order 8 of the 9" flex diffusers. I have the two 110 watts air pump that put out 110 lpm (3.8 cfm) 

Because the discs have 1/2" inlets and they have data on the performance of the discs and usable air pressures etc. I am really really thinking about buying a proper commercial air pump, not these silly ass super hot mini compressors. I'm thinking about this one: http://www.ebay.com/itm/Thomson-120w-REGENERATIVE-ROTARY-Air-BLOWER-COMPRESSOR-10cfm-30-H20-ULTRA-Quiet-/120842909083?pt=BI_Pumps&hash=item1c22cc759b#ht_644wt_922


For the cost of a small pump I can get quiet, cool air and three times the volume. 
I can run a hard line to each disc with a simple grommet through the grow bucket. It seems that it will have enough pressure an these are the types Of pumps that sewage treatment plants etc use to power their air diffusers. I just need to run the pressure and flow loss calculation. 

Woodsman.. What you think of that thing? I just hate that airline is so damn small


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## woodsmaneh! (Jan 14, 2012)

Never seen them before, looks intresting.....


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## mike91sr (Jan 15, 2012)

woodsmaneh! said:


> I don't agree, if you take a 1" blue and a 1" ceramic on the same pump it will out perform the blue hands down. The size of the bubbles and quantity of bubbles is far better with the ceramic than the blue. IMHO
> 
> Just put the 2 side by side and you will see a difference.
> 
> ...


I couldn't agree more about avoiding cheap purchases. I buy quality whenever I can, though I have to admit cutting a few corners here and there. I don't think this discussion/write-up really concerns the people who are buying the cheapest shit they can get down at the local hydro shop without thinking twice, it's more for people who are trying to improve their systems or design an efficient one in the first place. 

So while I'm not trying to be a cheap-ass, there has to be a substantial improvement to justify numerous stones of this cost. With a waterfarm 8 pack and 2 dwc buckets, Id be spending over $200 on air stones as opposed to $10. To see any real improvement, I'd also have to buy a larger air pump. I currently run a 110l/min, so upgrading isn't the cheapest thing in the world. The pump legallyflying linked is almost $200, totaling nearly $400 with stones to upgrade. Or I buy twice as many cheap blue stones to handle the extra air, and only spend $220. And I still have a hard time believing any noticeable difference will be seen provided they're both on this same pump. 

Again, I totally agree with using high quality products, but only if they're justified. And this test did nothing but prove that the investment is better spent on a larger pump than air stones. 

Lastly, great article you posted. I didn't really think about air temps that way before. My commercial pump runs hot as fuck so I'm thinking of relocating it to the outside of my tent into the air conditioned room. At least that way it will be pulling air thats in the 60s as opposed to mid-70s


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## UnderCurrentDWC (Jan 15, 2012)

^^^^
My commercial pump also ran hot so hot I couldn't touch it, now I've dedicated a fan blowing over it 24/7, that's taken care of the excess heat and provides fresh cool air for the system.


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## sqydro (Jan 15, 2012)

Mauler57 said:


> Always good to see a comparisons and reports on anything that will save me $$$ and optimize my grow conditions. REP+ my friend


if u wanna save money and optomise go with no airstones at all and no air pump or line, use waterfall effect for DO same if not more DO and less equip = more efficient! 

great test OP ++ rep i have a DO meter but need to find a tooll to open it lol then im doing a flooming v air stone v waterfall effect DO test, as u say and have prooved, temps is the most important of all!!


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## Huel Perkins (Jan 15, 2012)

Legallyflying, any thoughts on my post above about doing some tests with h2o2?


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## woodsmaneh! (Jan 15, 2012)

Lets see if you bought 8 of the 7" vs the 9" the cost would be 15$ each vs 16$ each so say

$120.00

http://www.diffuserexpress.com/catalog/flexair_threaded_disc_diffusers.html

and a pump say $94.00

http://www.sunlightsupply.com/p-11512-ecoplus-commercial-air-pumps.aspx

so that's $214.00, never have to buy another stone, you get 10x the bubbles and the bubble size is .500 vs 6000 for a blue stone.

I guess the choice comes down to $$ vs return

If you were getting 2 oz x 8 buckets = 448gr
If you saw a 10% increase in yield = 44 gr more = paid for 2x over by increase

so even a 5% increase would make it well worth it 5% 22gr x 5 x a year = 110 extra gr a year plus you have the equipment and happy plants.


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## woodsmaneh! (Jan 15, 2012)

Hydrogen Peroxide and Horticulture
By Bryce Fredrickson 
Hydrogen Peroxide (H2O2) is a clear sharp smelling substance very similar in appearance to water (H2O). Like water it is made up of Hydrogen and Oxygen, however H2O2 has an extra Oxygen atom in an unstable arrangement. It is this extra atom that gives H2O2 its useful properties. H2O2 has been used for many purposes including cleaning, bleaching, sterilizing, rocket fuel, animal feed treatment and in addition many miraculous claims about its health benefits have been made. This article isn't about any of these; instead it will concentrate on horticultural applications. H2O2 is of great use for both hydroponics and dirt/soilless gardening. 
1. What Does Hydrogen Peroxide do?
H2O2 is an unstable molecule, when it breaks down a single oxygen atom and a molecule of water is released. This oxygen atom is extremely reactive and will attach itself to either another O- atom forming a stable Oxygen molecule or attack a nearby organic molecule. Both the stable and O- forms will increase the level of dissolved oxygen. This is the method by which H2O2 is beneficial. Pretreating the water supply with H2O2 will drive out the Chlorine many cities use to sterilize it. This will also degrade any pesticides or herbicides that might be present as well as any other organic matter. Well water can be high in methane and organic sulfates, both of which H2O2 will remove. Many disease causing organisms and spores are killed by Oxygen, the free Oxygen H2O2 releases is extremely effective at this. H2O2 will help eliminate existing infections and will help prevent future ones. It is also useful for suppressing algae growth. The free Oxygen atom will destroy dead organic material (i.e, leaves roots) in the system preventing them from rotting and spreading diseases. 
2.Over Watering
Roots require Oxygen to breathe and low levels are the main cause of almost all root diseases. Both soil and hydroponic plants often fall prey to the same syndrome although it is rarely recognized as what it really is. Hydroponic crops often fail due to "root rot" and soil crops succumb to "over watering." The real cause of both these problems is a shortage of Oxygen at the root zone. In a soil system the soil consists of particles, a film of water on the particles and air spaces between the particles. When too much water is put into the soil the air spaces fill with liquid. The roots will quickly use up what Oxygen is dissolved in the water, if they haven't drunk enough of the liquid to allow air back in to the soil spaces they will stop working. In this situation roots will start dying within twenty-four hours. As the roots die the plants ability to drink water and nutrients will decrease, this will cause symptoms of nutrient deficiencies (mostly pale, slow, weak growth), and strangely they will start to wilt like they don't have enough water. It is easy to make a fatal mistake at this point and add more water. 
In a Hydroponic system the cause is a more direct simple lack of oxygen in the solution, this may be from inadequate circulation and/or aeration. High reservoir temperatures also interfere with Oxygen's ability to dissolve in the water. Temperatures above 70F (20C) will eventually cause problems, 62F-65F (16C-18C) is recommended. The same symptoms will appear as with soil plants but you can also check the roots. Healthy roots should be mostly white with maybe a slight yellowish tan tinge. If they are a brownish colour with dead tips or they easily pull away there is at least the beginnings of a serious problem. An organic dirtlike rotting smell means there is already a very good chance it is too late. As roots die and rot they eat Oxygen out of the water, as Oxygen levels are even further depleted more roots die, a viscius circle may be well under way. Reduced Oxygen levels and high temperatures both encourage anaerobic bacteria and fungi. The plants may still be saved but you will have to work fast. 
3. How Hydrogen Peroxide prevents root rot/overwatering.
When plants are watered with H2O2 it will break down and release Oxygen into the area around the roots. This helps stop the Oxygen from being depleted in the water filled air spaces until air can get back into them. High Oxygen levels at the roots will encourage rapid healthy root growth. In a Hydroponic system H2O2 will disperse through out the system and raise Oxygen levels as it breaks down. Strong white healthy roots with lots of fuzzy new growth will be visible. This fuzzy growth has massive surface area allowing for rapid absorption of the huge amounts of water and nutrients needed for rapid top growth. A healthy plant starts with a healthy root system. 
4. How to use it.
H2O2 comes in several different strengths 3%, 5%, 8% and 35%, also sold as food grade Hydrogen Peroxide. The most economical is 35% which we recommend be diluted to three percent before using, as at this high concentration it can cause damage to skin and clothing. When working with food grade H2O2 it is very important that you clean up any spills or splashes immediately, it will damage almost anything very quickly. This is extra important with skin and clothing. Skin will be temporarily bleached pure white if not washed cleaned. Gloves are strongly recommended when working with any strong chemical. 
Food grade H2O2 can be diluted to three percent by mixing it one part to eleven parts water (preferably distilled). The storage container should be opaque to prevent light from getting in and it must be able to hold some pressure. If three-liter pop bottles are available in your area they are ideal for mixing and storing H2O2. There are twelve quarter liters (250ml) in three liters, if you put in one quarter liter H2O2 and eleven quarter liters (250ml) water in the bottle it will full of three percent H2O2 and the bottle can hold the pressure that the H2O2 will generate. Three percent Hydrogen Peroxide may be added at up to three ml's per liter (2 1\2 tsp. Per gallon), but it is recommended that you start at a lower concentration and increase to full strength over a few weeks. Use every watering even on fresh cuttings. For hydroponics use every reservoir change and replace twenty-five percent (one quarter) every day. Example: In a 100L reservoir you would add three hundred ml's (3%) H2O2 when changing the nutrient. You would then add seventy-five ml's more every day. 
5. Where to get it.
35% food grade: called food grade because it has no toxic impurities
Of course your local hydroponics retailer, whom you can locate over the web at www.hydromall.com. Direct order off the web (there may be shipping restrictions on high strength peroxides). H2O2 is used to bleach hair so the local hairdresser may have a source. The local feed supplier may have it in small towns. Prices range from fifteen dollars per quarter liter to eighty dollars a gallon. One gallon will treat up to fifty thousand liters of water. 
3%5%, 8%
Can be found at most drugstores or pharmacies, prices start at a less than a dollar for a one hundred-ml bottle that will treat one hundred liters. 
6. What to do if you already have root rot. 
In Dirt:
Use peroxided water with anti-fungicide (benomyl) and a high Phosphate fertilizer (9-45-15, 10-52-10, 0-60-0) for root growth. Root booster (5-15-5) or any other product with rooting hormone dissolved in it is helpful in regrowing roots and is strongly recommended. If a plant is wilty adding Nutri-Boost may save it. Water heavily until liquid pours out the bottom of the pot. This sound like bad idea, but it flushes out stagnant dead water and replaces it with fresh highly oxygenated water. Don't let plants sit in trays full of water, the soil will absorb this water and stay too wet. Don't water again until the pot feels light and the top inch or two of the soil are dry. 
In Hydro:
Change your nutrients. Add H2O2 to the system. This will add oxygen and chemically eat dead roots. If roots are badly rotted and can be pulled away by hand you should pull them off. They are already dead and will only rot, causing further problems. Add a fungicide to kill any fungus that is probably present in the rotted tissue to prevent it from spreading. Root booster will speed recovery. If plants are wilty Nutri-Boost may help save them. Increase aeration of the water, get an airpump and air stones, or more of them, for the reservoir. An air stone under every plant is usually very effective, but will require a larger air pump. Models that will do from forty to four hundred stones are available. Decrease the reservoir temperature, oxygen dissolves better in cold water and disease causing organisms reproduce slower as well. A good temperate range is 62F to 65F; anything above 70F will eventually cause a problem. It is also a good idea to remove any wilty plants from the system and put them on a separate reservoir so they don't infect plants that are still healthy. 
Summary
The key to big productive plants is a big healthy root system and Hydrogen Peroxide is a great way to keep your roots healthy. It is a must to ensure the biggest best crops possible and to increase the chances of your plants thriving to harvest. Peroxide users will rarely lose plants or crops to root disease and will harvest larger and more consistent crops.


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## mike91sr (Jan 15, 2012)

woodsmaneh! said:


> and a pump say $94.00
> 
> http://www.sunlightsupply.com/p-11512-ecoplus-commercial-air-pumps.aspx
> 
> ...


I have an air pump bigger than that (not the 280, mine is 112w). So I don't think the stone change would make a difference in total DO, as legallys test proved. No stone, unless it's too small/restrictive for the pump it's attached to, will make a difference. The expensive diffusers, with the smaller bubble size and 10x as many, still made no difference. 

I agree, an upgrade in the pump would be worth it, and only then would a stone upgrade be worth it, and even at that point I'd want a comparison to see if the stone is a limiting factor before I get more expensive ones. I couldn't find max airflow ratings for the cheaper airstones, so I don't know exactly at what point you'd want to get larger stones. I can tell you that with 8 stones hooked up to my 112w, 110l/min pump, there is a noticeable difference in the airflow from each stone if I close one of the open valves. This means my pump is not able to max out airflow through these stones, so no amount of money spent on any type of stone will make a difference larger than what legally's test proved. 

So I don't think I'd see the hypothetical returns you're talking about. Although a pump upgrade is in my long-term plans. 

Do you have any info on max airflow for stones besides the flexair? They're the only ones that seem to say it.


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## legallyflying (Jan 15, 2012)

Woods and I are growing in RDWC. Well, my new RDWC is almost finished..but anyways; for those growing in DWC it's NOT about DO. DO is easily achieved. What you really need is bubbles moving across the roots. If it were only about DO then even a 4" clogged airstone would achieve maximum DO. 

While a waterfall..or whatever would probably reach max DO I wouldn't rely on it for anything except flood/drain. 
The more air the better. Can't wait for my discs to get here


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## mike91sr (Jan 15, 2012)

Right but wasn't the entire point of your test to disprove the need for expensive diffusers? I get that more air is better, but your results are showing that a bigger pump is what you need for more air, not a better stone. 

Also, how do you mean that a 4" clogged stone will max out DO? Less airflow=less DO (temp constant). And what makes the difference between DWC/RDWC as far as bubbles vs DO?


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## legallyflying (Jan 16, 2012)

What I am saying is that the maximum do for a given temp is easy to reach. You could probably do that with a POS clogged air stone. From the testing it was fairly obvious. DO means dissolved oxygen. Just because the solution has reached its maximum dissolve air content doesn't mean that more air isn't good. That is where the dwc comes in. Air bubbles passing over the roots will still increase the oxygen content of the root. ABOVE that of the DO level. Comprende? 

Clogged air stones means lost crops and that is why those that are serious about all this shit...yet still find the time to come in here and explain it all, spend there money on the best clog free airstones they can find 

Happy growing


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## Illegal Smile (Jan 16, 2012)

DO isn't the only function of airstones. I want those bubbles to feed my DWC grow until roots are in the water. Then any airstone will do. My Boss Hog doubles work better for me than anything else.


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## mike91sr (Jan 16, 2012)

legallyflying said:


> What I am saying is that the maximum do for a given temp is easy to reach. You could probably do that with a POS clogged air stone. From the testing it was fairly obvious. DO means dissolved oxygen. Just because the solution has reached its maximum dissolve air content doesn't mean that more air isn't good. That is where the dwc comes in. Air bubbles passing over the roots will still increase the oxygen content of the root. ABOVE that of the DO level. Comprende?
> 
> Clogged air stones means lost crops and that is why those that are serious about all this shit...yet still find the time to come in here and explain it all, spend there money on the best clog free airstones they can find
> 
> Happy growing


I'm pretty sure you and I are agreeing, with different wording. My point has been that the stone is not the determining factor, rather the pump's total air output. With the extra water turbulence provided by the cheap blue airstones as opposed to the diffusers(in my dwc bucket, not rdwc), more oxygen will get to the roots, even though it's not dissolved. 

I understand if the goal is to avoid clogs, but that doesn't necessarily make the stone better in any other aspect. If max DO is reached with the cheap stones, DO won't change with the diffuser anyway, again assuming temp is constant. And for the total airflow to not matter in RDWC, I assume you aren't putting an individual stone in each container, but just in the res? Otherwise there would be no difference in the systems. So the only benefit I see is that they don't clog. That still doesn't justify a 9" round diffuser to me, as there's no difference at all between that and cheaper, smaller diffusers. Again, unless you're running a pump that can push more air than your stones allow, which would take one hell of a pump.


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## legallyflying (Jan 16, 2012)

I'm pretty sure we are not on the same page...LOLYes, there are air stones in every singe container. You seem to underplay the importance of the "only" benefit of not clogging. I see that as one of the most important aspects of an airstone. I have had all of them clog, even the expensive micropore diffusers. The other thing to consider (in DWC or RDWC) is the coverage AREA of each stone. When the container gets full of roots, the bubbles tend to be really concentrated above where the stone is. So a little blue stone only produces a tiny swath of bubbles where as a big disc produces a huge column of bubbles. I hope this makes sense. THere seems to be a lot of confusion about air stones and the need for air, etc. From the myth that "bubbles don't infuse oxygen until the break on the surface" which is really pretty stupid if you no anything about physics, to the thought that max DO is THE goal. IN DWC and its variants you want max air and max area in a stone that will resist clogging. Looking at the numbers, the 9" flex air stones really don't have any disadvantages at all. Maybe the price but $16... come on man, that is not much money for a single purchase that will last years. I've got about $800 worth of light bulbs that were only used for 6 months sitting on my shelf.


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## mike91sr (Jan 16, 2012)

You haven't really addressed my points directly. I agree with pretty much everything you're saying, and you just confirmed that we are on the same page....besides two things. I misunderstood your airstone configuration in the RDWC, which still doesn't change the application of the theory your test proved. Second, the stone area is what gives smaller stones a better penetration into a dense root system. Again, yes, a larger stone will provide the same amount of air over a greater area, but again, without a big enough pump to power that airstone beyond the capacity of the cheaper stones, there's no difference. The bubbles will be in low concentration with no pressure, so I don't think you'll see the same results with the "better stone" just because it's bigger. Again, *unless you change the pump*. 

Although DO is not the be-all, end-all, it doesn't mean it's not an important factor in the equation. Besides, this entire thread was based on the efficiency of dissolving oxygen with different stones. My entire point has been based on your test and it's application. The stone makes no difference.*

Even still, I stand by the fact that, on the same pump, it won't be any better. Legally's test proved that 2x6" is worse than 1x6". So on a pump realistically sized for most setups, same problem with your stone.​
​
*Wasn't that the point of your test? All I'm doing is restating the results you found: a bigger pump is needed for an improvement, not a stone change. Without a bigger pump, the stones are NOT the limiting factor in the equation.


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## woodsmaneh! (Jan 16, 2012)

mike91sr said:


> You haven't really addressed my points directly. I agree with pretty much everything you're saying, and you just confirmed that we are on the same page....besides two things. I misunderstood your airstone configuration in the RDWC, which still doesn't change the application of the theory your test proved. Second, the stone area is what gives smaller stones a better penetration into a dense root system. Again, yes, a larger stone will provide the same amount of air over a greater area, but again, without a big enough pump to power that airstone beyond the capacity of the cheaper stones, there's no difference. The bubbles will be in low concentration with no pressure, so I don't think you'll see the same results with the "better stone" just because it's bigger. Again, *unless you change the pump*.
> 
> Although DO is not the be-all, end-all, it doesn't mean it's not an important factor in the equation. Besides, this entire thread was based on the efficiency of dissolving oxygen with different stones. My entire point has been based on your test and it's application. The stone makes no difference.*
> 
> ...


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## woodsmaneh! (Jan 16, 2012)

*Take a look at at the air bubbles produced by an aquarium aerator. Watch how quickly the bubbles rise to the surface. They provide little 
aeration, but are aesthetically pleasing to watch. Bubbles must remain contacting the water, if they are to do the job properly. A good rule of thumb 
is: The smaller the bubble, the longer it will remain suspended in water to dissolve.*​


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## legallyflying (Jan 16, 2012)

WHats the best bet? A big PUMP and a BIG stone. 

Woodsmen, I have been researching the regenerative blower I linked to above. I found one post where a guy was using it in a hydro setup but he had 1.5" plumbed all the way into his buckets. Then he was using the big square airtones with the 1/2" inlet. 

The blowers move ALLOT of air, but at a much lower pressure. I think the pressure on them is around 1.5 PSI Like this model : http://www.ebay.com/itm/Thomson-HRB250w-electric-REGENERATIVE-ROTARY-RING-BLOWER-COMPRESSOR-reg-365-/120838112156?pt=BI_Pumps&hash=item1c2283439c#ht_500wt_946 For the same wattage you are getting 5X the amount of flow but you ahve to have some bigger plumbing or you are going to loose a bunch of pressure. I used some calculators to deal with pressure loss and it seems that If I T that blower outlet into a 2" PVC running down the side of my rows and then T off into 3/4 pipe into each bucket with a flex seal disc that I would loose approximately .4 psi. So we are only dealing with 1lb per square inch...not a whole lot at all. I need to call the flexs air folks as they don't give operating pressures.


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## mike91sr (Jan 16, 2012)

legallyflying said:


> Also of note was the "super mega micro diffuser" the gold standard of airstone..I mean, its got micro fucking bubblles man! ..scored middle of the pack. Going to pass on more of those.
> 
> The 6" blue stone and the 2" round stone moved much more water than all the other stones, it was visibly more. I mean the water was just boiling. The lowest water movement came from the bubble hose and the micro diffuser.
> But if you can get the same results by saving shit tons of money on the actual air stones..it may be worth it to buy a proper airpump.
> ...


This is why I assumed we were on the same page. I wasn't aware your outlook on the subject had changed since then. And of course a bigger pump + bigger stones is the best solution. But that was never the argument as the subject was originally about air stones exclusively. 




woodsmaneh! said:


> First off a 6" blue stone vs a 6" ceramic with the same pump = ceramic hands down.


 Legally's test proved the exact opposite of that. 


woodsmaneh! said:


> The reason is the ceramic has a higher density = more bubbles and smaller bubbles = better plants.



Yes the bubbles are smaller but the same amount of air is being let through a larger surface area so they're actually less dense, even if they're smaller. Legally's point was that the greater surface area is better. Mine is that a smaller area and greater total airflow means greater penetration into a dense root mass. I'd really like to see a side-by-side before believing all of those things, which aren't all correct anyway, actually result in better plants.


woodsmaneh! said:


> Your pushing the same amout of air


Exactly!!


woodsmaneh! said:


> the blue stone has less resistance due to larger porosity =bigger bubbles = not the best.


Why not? DO is already maxed out. If you ask me, less resistance due to larger porosity=bigger bubbles with higher pressure=great rootmass penetration=better. 


I'm not trying to be a douche and just aimlessly argue here, but the thought process of just buying more expensive items despite proof that they're no different than the cheap version has become a huge problem within the hydroponics industry. And because both of you are clearly intelligent growers who don't just fall for the hype and bs marketing tactics thrown at you, and both have skills and knowledge that greatly outshine mine, I'm kind of shocked that you're both arguing against the results of an experiment designed to answer all of these disagreements.


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## Weedasaurus (Jan 17, 2012)

interesting results. thanks for doing the research. So I guess this is one of the areas where your money isn't well spent. I wonder if you combine the airstones with a venturi pinwheel pump if you'll get even more air.


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## legallyflying (Jan 17, 2012)

This thread is a great example of why I spend little time on this site anymore. 
You try to help out but then inevitably you spend your time trying to convince some douche nozzle the realities of the situation. Woodsman is an extremely experienced grower who knows his shit front and back and yet douche #4,567 --Mike91sir feels the need to line by line debate him on the information that in my experience is accurate and correct. 
Allow me to summarize the results of the test for those that can't seem to get a grasp on things..
For those growing in any method besides DWC or RDWC it became pretty clear that pretty much any airstone will do the job. If your just aerating your rez get a small airpump and a single stone.. done.

But for those utilizing DWC, things get more complicated..which should be no surprise. So here are a couple guidelines and things to remember
1. The principle method that air is entrained in solution is by bubbles passing through the solution
2. Given the same volume of air; smaller bubbles have way way way more surface area than bigger bubbles. 
3. DWC buckets quickly get filled with roots.. there is no "turbulance" or "mixing"going on within the root zone. A little, but really not much. 
4. THEREFORE, smaller bubbles are better. 
5. Clogged stones will spell disaster in DWC..quickly. I was running living DWC so my stones were more prone to clog but I found that the blue stones clogged first, then the cylinders, and the micro pore was close behind. 
6. When clogged, the micro pore gave off the least amount of air. 
7. You need WIDE coverage of bubbles in DWC due to the sheer amount of roots. The broader your container the more important this becomes. 
8. Resistance to clogging is one of the most important aspects of a DWC airstone, as is surface area. 
9. I would say that your flow rates per container in DWC should be around 20 LPM. 
10. There is no such thing as too much air, ALWAYS err on the side of more air. More air typically results in better performance. 
11. The best air stone/ diffuser on the market? Even though I haven't used it yet, the flex air discs seem to be the IDEAL airstone. high flow rates, smaller bubbles, larger surface area and virtually impossible to clog due to their design. All that for $15.. shit man, sign me up!!
12. Best air pump on the market? Probably the alita but jesus are the expensive. I'm looking into using a blower but this requires very specific plumbing. 

The big take away? don't be a cheap fuck, buy quality gear and check that off the list of things that can go wrong.


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## mike91sr (Jan 17, 2012)

You can hate on me all you want and call me a douche for debating in a discussion board, but it doesn't change the fact that you have not even defended your change in outlook compared to the first post you made in this thread. I've been trying to get both of you to address my points head-on because I have a genuine interest in finding out why you think my theory is so asinine, but neither of you will, so we just keep repeating the same banter and now you're throwing a fit. 

So I made it very clear how I'm presenting my argument point by point. Not my fault that offends you since you can't address those points directly. I even gave both of you respect but now you come and attack me personally for what reason? Because I don't just want to believe you, and question your opinions?? I'm just trying to wrap my head around why you are contradicting yourself. Every point you made in your last post is essentially true, but neither of you have yet to actually address and disprove my theory in itself. As I try to explain the logic behind my argument and against yours, point by point, I still cannot get an answer from either of you. 

I think the big take away is that if you cannot explain why you are going to contradict the results of your own study, the thread should be locked immediately after the write-up is posted. I'll leave your thread now since there's no longer anything useful coming of it.

Happy growing, smoke a j and chill the hell out bro


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## legallyflying (Jan 18, 2012)

All u need to know is posted in the list above. Why am I not going to waste my time to prove that some of your assumptions are incorrect? Why would I? The thread evolved from the original test, I'm not contradicting anything. The original point was any airstone will achieve max DO. I went with the cheap airstones and they clogged up pretty damn quickly and the didn't have enough size to distribute air evenly....sure they were maxing out DO when I tested the buckets but that wasn't good enough. Again, this is for the DWC folks. 

This kind of reminds me of the thread where a guy was insisting that it was the turbulence on the surface that entrained the oxygen, that the bubbles passing through the water didn't do anything. Nothing I could say would convince him otherwise.


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## Big P (Jan 18, 2012)

sup guys I got my Flexair 7" Diffuser in the mail yesterday. It look large.








do you think this air pump can power a 7" flexdisk?










This high output pump (394 gph/ 24,800 cc/minute capacities) has four adjustable 
1/4" outputs or valves that can be teed off to power up to twelve additional 
WaterFarm units. In addition, growers who use our Dual Diaphragm air pump can 
use it to reliably oxygenate their reservoir with air stones. Draws 8 watts.


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## Big P (Jan 18, 2012)

ima test it out tonight with my above air pump. I guess it should work.


lol im putting 7" flexdisk in a 10 gallon tub with 1 plant and the above air pump.



OVERKILL huh  thats how we do.


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## UnderCurrentDWC (Jan 18, 2012)

^^^^^

That dual diaphragm air pump is my favorite, however it only produces 20lpm, which is only enough air for one individual grow bucket, the diffuser you show will peak out @ 30lpm, so one DD air pump, 1 Flexair in 1 grow bucket is what I would recommend.


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## legallyflying (Jan 18, 2012)

I am wondering how you plan to attach the flex air to the pump? I have gone back and forth and back and forth about how I should do it. It has a 3/4 inch male pipe thread so I was thinking that I would run 1/2 line from my one 110 LPM pump and then just t off to each of the 4 buckets with a 1/2 inch line through a gromet and then connect via a 3/4 x 1/2 elbow barb. It just seems "gay" for lack of a better word as the outlet on my pump takes a 3/8 hose and I can't find a replacement barb for it. 

I guess it doesn't matter. 

That pump is not really impressive. It has an outlet volume of .81 CFM (CFM seems to be the standard for industry calculations on pumps and diffusers). The design flow rate for the 7" is 0.5 to 2.5 so your definitely on the low end of the spectrum. The good news is that you will have more than enough PSI to drive the diffuser. 

The cheapest high volume pump is the active air 110lpm which you can get for around $70. I am using this for 4 buckets achieving 0.98 CFM. The downside is that they run HOT.


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## UnderCurrentDWC (Jan 18, 2012)

One advantage of the dual diaphragm pump is the energy savings, they run @ .4watts per lpm, my big commercial pump runs @ 1.2 watts per lpm + I have to cool it with a fan adding more watts per lpm. Over time they save you a boat load of money, anything that runs 24/7 in my opinion should run as efficiently as possible. 
Another advantage of one air pump per grow bucket in a rdwc is if one pump fails the system will still be able to support itself till you can fix the problem pump.

I do think attaching this 1/4" air pump to a 3/4" flexair diffuser could be a problem, however I think Big P providing 20lpm to 1 plant is right where he should be.


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## Big P (Jan 20, 2012)

sup guys, unfortunatly I just found out my grow has been severly comprimised so I had to kill my plant and destroy all the incriminating evidence, but I did get a chance to try and connect the 3/4" flexair to the dd pump,


I took the mettal valves part off the below pump:









then i got a 1/2" plastic T:







i purchased large & small plastic tube all differnet sizes:












also some duct tape:










then I jerry rigged it to connect.

but the problem was the thing floats meanly and makes too much noise. lol I guess it doesnt matter now cuz I cant grow anymore because of some bullshit!! 

thanks for the replies.


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## legallyflying (Jan 21, 2012)

Shit man, sorry to hear that. For future reference I just made my mounts for the flex discs. Mounting it on a rigid pipe will prevent it from floating. I used 1/2" PVC pipe and male and female PVC conduit fittings with a rubber o ring to pass through the side of the container. 

3/4 mpt x slip > 3/4 x 1/2 reducer > 1/2" pipe > PVC coupling through the container > 1/2" T. Then I just hard piped them all together and then ran them to a hose barb and then the air pump


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## woodsmaneh! (Jan 21, 2012)

I put a 1/2 barb on it than added a brick to keep it down in the Jumbo and ran a 1/2 pvc to it for the UC.


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## PetFlora (Jan 21, 2012)

I have 4 HPA grows where atomized mist feeds the roots periodically. 

My interest is for the *seedlings/clones bubbler*, where the greater the amount of tiny bubbles breaking the surface the more O2/nutrient rich the air space above to feed the young developing roots. I am currently using a 15L/min pump (4 head manifold) but plan on replacing it with DD pump. Prior to this, I was using an Elite 802 (2 heads) and noted good root development, but nothing like this. 2 days ago, this plant had no visible roots exiting the net pot!  I just transferred it to the HPA.


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## legallyflying (Jan 21, 2012)

I'm planning on using a similar set up for rooting before going into the UC. 

My active air pump took a crap on me so I opened it up. Jesus what a piece of shit. No wonder it runs so goddamn hot. The other thing I found out. There air pumps have zero warranty none. Nada zilch. So I have a 4 month old pump that they dont sell parts for and they won't warranty it. They might as well say "buy this hot piece of shit then go fuck yourself" right on the box. Such a flawed design, super thin rubber gaskets in a high heat high psi application. 

I will never ever buy another hydrofarm product again!!! I guess their idea of commercial grade is having enough money to just throw shit out


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## woodsmaneh! (Jan 22, 2012)

Dam I hate that, well I have purchased these and they are good but $$ caddy of pumps

http://www.hakkoairpumps.com/subcat31.html

I have 3 of these they are inexpansave and I have not had any issues with them I have 280watt and 80watt pumps they have warrenty and parts are avalible.

http://www.sunlightsupply.com/p-11512-ecoplus-commercial-air-pumps.aspx


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## legallyflying (Jan 22, 2012)

I don't know man, those look like the same pumps as mine. I like the look of the other pump and have seen a couple knock offs or unbranded pumps that look identical to the alita. you know how that goes, they may be made by the same factory...just on the third shift This one is cranking out 150 LPM..http://www.ebay.com/itm/Aquarium-Air-Pump-Air-Volume-9150-cu-in-min-Pressure-6-53-psi-100-watt-/170754907001?pt=LH_DefaultDomain_0&hash=item27c1c91b79#ht_500wt_1244here are some pictures of my diffuser hook ups; pretty straight forward and I really like the idea of not having them float or move around.


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## woodsmaneh! (Jan 26, 2012)

*http://www.uoguelph.ca/research/apps/news/pub/article.cfm?id=90*

*Higher dissolved oxygen great for productivity, health and vigor*
Research > Learn About Research > News > Higher dissolved oxygen great for productivity, health and vigor 
[HR][/HR]​*By Robert Fieldhouse
(Guelph, October 13, 2005)*
Dissolving more oxygen into hydroponic solutions could boost greenhouse productivity and provide a whole host of other benefits too, say University of Guelph researchers.
Prof. Mike Dixon and Dr. Youbin Zheng, Department of Environmental Biology, are investigating the positive aspects of using an oxygen diffuser to increase oxygen levels in greenhouse hydroponic solutions used to grow roses, tomatoes, cucumbers and peppers. 

*Dr. Youbin Zheng, Department of Environmental Biology, is studying if oxygen levels can be boosted in hydroponic solutions to help growers ward off harmful microbes and boost productivity. *

_Photo credit: Olivia Brown _
Preliminary results suggest a higher dissolved oxygen level increase productivity, health and root vigor in greenhouse plants, and helps keep harmful microbes in check.
&#8220;These findings are really beneficial to the industry,&#8221; says Zheng. &#8220;If we can use oxygen to boost plant health, making them stronger and more resistant to disease, we've discovered a very helpful tool.&#8221;
Oxygen isn't as prevalent in warm water as in cool water, so oxygen levels tend to be low -- about two to four parts per million (ppm) -- at high greenhouse temperatures, compared to eight to nine ppm in cool water. Under hot weather in the greenhouse, the root zone is especially short on oxygen, says Zheng, because root respiration depletes oxygen in hydroponic solutions. Excessive watering can further depress oxygen levels because it makes growth media, such as rockwool or coconut fibre, less porous, blocking air. These factors all weaken plant disease defense systems, making them more susceptible to disease-causing microbes such as _Fusarium _and _Pythium _which cause root decay.
To prevent this problem, greenhouse growers typically bubble air into hydroponic solutions to bring oxygen levels up to about nine ppm. But sometimes this still isn't enough.
Two years ago, the BC Greenhouse Growers' Association asked Dixon to investigate using even higher oxygen levels in hydroponic solutions. His literature review revealed that very little work had been done in this area suggesting the problem was largely ignored &#8211; until now.
Dixon and Zheng are using an oxygen diffuser recently developed and manufactured by Seair Diffusion Systems Inc., an Edmonton-based company with an interest in the greenhouse sector. The diffuser concentrates atmospheric oxygen, and dissolves it into hydroponic solutions. With this technology, oxygen levels can reach as high as 60 ppm in hydroponic solutions.
The research team is currently studying the effects of different oxygen levels, ranging from about nine ppm to 40 ppm.
So far, preliminary results are promising. But creating optimal supersaturated oxygen solutions requires extreme precision. Oxygen can be damaging at very high levels, says Dixon , so it's important to establish application methods for using this technology for different crops.
But if the methods can be worked out, Dixon says the oxygen diffusers are inexpensive and stand to emerge as an economical, environmentally friendly solution for growers looking to enhance their crops.
&#8220;Greenhouse growers are voracious technical consumers &#8211; they'll try anything,&#8221; says Dixon . &#8220;But by the same token, they're also very shrewd business people, and they won't waste money unnecessarily.&#8221;
Dixon and Zheng will continue their research and will further investigate oxygen's effect on plant growth, physiology and disease. For example, they will inoculate greenhouse plants with specific microbes to see how the plants cope with this challenge under different oxygen levels.
Other researchers involved in this project include technician Linping Wang, graduate student Johanna Valentine and undergraduate student Mark Mallany, Department of Environmental Biology.
This research is being conducted at greenhouses in Guelph and Leamington , Ontario . It is sponsored by Seair Diffusion Systems Inc., Flowers Canada Ontario and the Fred Miller Rose Research Fund.


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## legallyflying (Jan 26, 2012)

Dude, we work on the same channels. I was JUST reading a journal of plant ecology paper on that very technology...

http://jpe.oxfordjournals.org/content/early/2010/12/06/jpe.rtq030.full


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## PetFlora (Jan 26, 2012)

I have Oxy stones but needed some more, so I bought one 4" fine cylinder and hooked it up to my Walmart twin air pump. The bubbles barely came out of the top but only closest to the incoming line. I thought the stone was defective. I then replaced the WMart pump with an Elite 802 and the bubbles flowed throughout the surface area of the stone. My rez never looked so clear.


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## flamdrags420 (Jan 27, 2012)

hey lf, if you do this test again, could you add a control portion to it via just the pump and a hose without an airstone? Or was this what the last thing on the test is (the 4' air tube)?
Thanks and keep up the great work


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## legallyflying (Jan 27, 2012)

The 4' airtube was one of those cheap hoses with the little hoses in it. It performed the worst out of all them. I doubt I'll do the test again. I summarized my feelings on the whole airstone thing above. 

I'll be doing a review of the diffusers once I have them installed.


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## flamdrags420 (Jan 27, 2012)

right on man
was just curious what the output of a tube off the pump with nothing attached to it.
thanks again


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## legallyflying (Jan 27, 2012)

Well. The flex airs arrived today. Dude, I'm pretty bummed. So I hooked for of them up to my 6psi 110 lpm pump. Not a whole lot of air coming through. Seems I don't have the psi to drive them properly. Just blowing through them with my mouth took quite allot of effort. 

So in the end. They are going back


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## mike91sr (Jan 28, 2012)

legallyflying said:


> *CONCLUSION*
> 
> What am I going to do for airstones? Well its pretty obvious to me is the cheap old standby..the 6" blue airstones. They are a buck a piece so when your done with a cycle, you can simply pitch them and buy new ones. For me that means $16 every 3 months as opposed to $320 for 16 of the micro diffusers.


Ok, so blue stones are the way to go according to the test, gotcha!!



legallyflying said:


> 11. The best air stone/ diffuser on the market? Even though I haven't used it yet, the flex air discs seem to be the IDEAL airstone. high flow rates, smaller bubbles, larger surface area and virtually impossible to clog due to their design. All that for $15.. shit man, sign me up!!
> 
> The big take away? don't be a cheap fuck, buy quality gear and check that off the list of things that can go wrong.


Blue stones aren't the way to go? Expensive diffusers are the best despite proof otherwise, duh!!! Makes total sense...



legallyflying said:


> Well. The flex airs arrived today. Dude, I'm pretty bummed. So I hooked for of them up to my 6psi 110 lpm pump. Not a whole lot of air coming through. Seems I don't have the psi to drive them properly. Just blowing through them with my mouth took quite allot of effort.
> 
> So in the end. They are going back


Wait, so the blue stones that YOU proved to be more effective, actually ARE more effective? And now, despite the fact that they're "worse", you're going back to them?

Glad this thread made it full circle finally. Wow...  And I'm the thick-headed douche who can't be told I'm wrong here....oh wait


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## legallyflying (Jan 28, 2012)

No. Your the kind of guy the gets one idea in his head and can't evaluate and process new information. Sorry if more hands on experience changed my point of view on things. But that's ok. You just keep on keeping on with what your doing. Check out your grow journal 13.9 oz of 2 600's? Yeah dude .32 grams per watt. Your rocking it!!


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## mike91sr (Jan 28, 2012)

legallyflying said:


> No. Your the kind of guy the gets one idea in his head and can't evaluate and process new information.


You are the ONLY person on this forum who has ever interacted with me that would say that. You're the one who refused to hear my points and address them. Where did you actually tell me any new information that I didn't evaluate or process? Because I see my posts presenting information that YOU refused to evaluate and process. 



legallyflying said:


> Sorry if more hands on experience changed my point of view on things. But that's ok. You just keep on keeping on with what your doing. Check out your grow journal 13.9 oz of 2 600's? Yeah dude .32 grams per watt. Your rocking it!!


First grow of my life and I pulled 2 oz per plant. So thanks.  I'm happy considering every problem I ran into, including a blown ballast mid-flower, failing a/c during summer in SoCal, recurring mite infestations from the start, soil acidity issues, etc. A first time grower diagnosing, treating, and curing all those problems, still getting prime quality nugs. My bad for not wanting to veg longer so I would have gotten more yield, I wanted to be smoking it before the year was over. As I have medical problems resulting from my time in the military, I do depend on the medicine's painkilling abilities and didn't want to pay top dollar at shops for hit-or-miss quality. So yes I will keep doing what I'm doing, which doesn't involve shipping back retarded (and retardedly expensive) products that I myself proved would have no benefit prior to their purchase. And if you're going to spout shit from your dicksucker about my skills, why look at the first month of my growing time? How about you take a look at what I'm doing now and what I learned in one grow??


edit: youre really good at deflecting. It wasn't until I moved on from this sillyness that I realized you did an excellent job at redirecting attention towards attacking me personally(again) instead of the subject of the thread, and the reason behind your original shit-talking: I called BS on your theory, you threw a fit and told me I'm an idiot and i'd never learn, then you realized you were wrong, and when I point it out to you and everyone who may want to get something useful from this thread, you just go back to your antics. Learning experience averted.


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## richinweed (Jan 29, 2012)

I was under the impression the gas exchange primarily happened at the surface were the air meets the water so to speak, if this is true its not the bubbles that count, they just facilitate the movement of the solution, thus allowing this surface exchange, any thoughts on that?


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## legallyflying (Jan 30, 2012)

Rich, that is a common misconception yet you see it time and time again repeated, especially in aquarium forums. Two substances (unless they naturally do not mix--like oil and water) of different concentrations will seek equilibrium with each other. It's about the concentration gradients between the two substances. As air passes through water, the different concentration of oxygen between the surface of the bubble and the water try to equalize and oxygen is transferred to the water. Indeed, if you have a tube deep enough, the bubbles would never make it to the top as all the gas would be absorbed in the water. 

Read the wiki link about fine bubble diffusers... http://en.m.wikipedia.org/wiki/Water_aeration

Oxygenation of water by surface disruption occurs because there is increased surface area of the water....the surface area in contact with the air. It's the same thing as a bubble really. This is how aeration works...passage of gas along the surface. By that the surface of the water.. Or the surface of a bubble (which also increases the surface area of the water as it is displaced by the bubble. LOL...I think you get it by now 


Undercurrent..you don't actually believe the bubble teaming bullshit do you? 

Mike, you feel free to chime in and tell me I'm wrong. No better yet, ask me to devise and experiment and test it in order to prove to you that I am right.


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## PetFlora (Jan 30, 2012)

My analysis, being a personal use grower, is that fine stones + really good pump with multiple outlets = a great seedling/clone bubbler or rez aerator . The fine stones create more small bubbles, which do a much better job of interfacing with the water/nutes. Is it creating small amounts of H3O or more likely H2O2, dunno, but my rez is pristine, and my seedlings and clones root really fast.


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## woodsmaneh! (Jan 30, 2012)

*The smaller the air bubble, the more slowly it will rise, giving it more time to dissolve in the water.*​*A large 20mm bubble has a volume of 4.19 cm3, and a surface area of 12.6 cm2.*
*You could make 260 small 3mm bubbles from the large bubble. They wouldhave a total surface area of 83.6 cm2. This is 6.6 times the surface of the 20mm bubble. **The small bubbles, can theoretically aerate 6.6 times as much water with the same amount of air.*
*Knowing the importance of air bubble size, the effectiveness of different aerator systems becomes readily apparent!**




*


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## woodsmaneh! (Jan 30, 2012)

richinweed said:


> I was under the impression the gas exchange primarily happened at the surface were the air meets the water so to speak, if this is true its not the bubbles that count, they just facilitate the movement of the solution, thus allowing this surface exchange, any thoughts on that?


 You could not be more wrong. ^^^^^^^^


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## mike91sr (Jan 30, 2012)

Legally, just stop trying bro...a simple read-through of this thread explains everything about you so well, we get it already..You're an ultrasmart scientist who devises an experiment to prove something, then does the exact opposite of what the science proved, then turns into a small child when somebody questions why you're going directly against your own results inexplicably, without ever actually saying anything useful in the process. So believe me, the last thing id do is ask you of all people to do another experiment lol.



woodsmaneh! said:


> *The smaller the air bubble, the more slowly it will rise, giving it more time to dissolve in the water.*​*A large 20mm bubble has a volume of 4.19 cm3, and a surface area of 12.6 cm2.*
> *You could make 260 small 3mm bubbles from the large bubble. They wouldhave a total surface area of 83.6 cm2. This is 6.6 times the surface of the 20mm bubble. **The small bubbles, can theoretically aerate 6.6 times as much water with the same amount of air.*
> *Knowing the importance of air bubble size, the effectiveness of different aerator systems becomes readily apparent!**
> 
> ...


Surface area only changes the speed of dissolution, not the solubility. It's still the same amount of oxygen. So while yes, in theory diffusers may be able to aerate 6.6x as much water in the same amount of time, it's only a matter of seconds for water to get just as oxygenated, and since our air supply is continuous, you're not even seeing any benefit from the main draw of the product.


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## woodsmaneh! (Jan 30, 2012)

mike91sr said:


> Legally, just stop trying bro...a simple read-through of this thread explains everything about you so well, we get it already..You're an ultrasmart scientist who devises an experiment to prove something, then does the exact opposite of what the science proved, then turns into a small child when somebody questions why you're going directly against your own results inexplicably, without ever actually saying anything useful in the process. So believe me, the last thing id do is ask you of all people to do another experiment lol.
> 
> 
> 
> Surface area only changes the speed of dissolution, not the solubility. It's still the same amount of oxygen. So while yes, in theory diffusers may be able to aerate 6.6x as much water in the same amount of time, it's only a matter of seconds for water to get just as oxygenated, and since our air supply is continuous, you're not even seeing any benefit from the main draw of the product.



"Surface area only changes the speed of dissolution, not the solubility. It's still the same amount of oxygen."

The purpose of all this discussion is what puts more DO in the water (blue stone, ceramic, edpm defuser) and what it comes down to is the smaller the bubble the more DO that is transferred to the water. Full stop.

Do you have an issue with that?


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## mike91sr (Jan 30, 2012)

woodsmaneh! said:


> "Surface area only changes the speed of dissolution, not the solubility. It's still the same amount of oxygen."
> 
> The purpose of all this discussion is what puts more DO in the water (blue stone, ceramic, edpm defuser) and what it comes down to is the smaller the bubble the more DO that is transferred to the water. Full stop.
> 
> Do you have an issue with that?


I do have an issue with that, as it's not true. I really don't get how you can even try to say that it is. Years of both physics and chemistry have demonstrated and proven it over and overas well as this specific experiment. It is fact, not theory that I'm talking about.


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## woodsmaneh! (Jan 30, 2012)

Yes it is true and proven by science, physics ect.

Almost all of the oxygen dissolved into the water from an air bubble occurs when the bubble is being formed. Only a negligible amount occurs during the bubbles transit to the surface of the water. This is why an aeration process that makes many small bubbles is better than one that makes fewer larger ones. The breaking up of larger bubbles into smaller ones also repeats this formation and transfer process.

So my point on bubble size above stands.

there are so many hits on it I guess you just forgot to use google??

Now stop calling people names and being rude, go find some science proof to make your point and come back to discuss because we appear to be chasing our tails.


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## mike91sr (Jan 30, 2012)

Google, really? You say its been proven, but as a bio major that has taken substantial amounts of chemistry and admittedly not nearly as much physics, I've read the exact opposite of what you're saying in numerous international subject references and scholastic journals. I asked you to do the same and you still haven't. Google henry's law. Or combined gas law. Pressure and temp can change solubility (amount of solute able to be dissolved into solvent). Surface area can change the rate of solution, and nothing else.

I have yet to be rude to you and legally is the first person ive ever gotten into a retarded internet argument with that was of a personal nature. You and I were in the middle of a technical disagreement when legally chimed in then got pissed that I didn't change my mind for him. I stand by everything I've said, and until somebody presents actual fact from a scholastic source with the evidence to substantiate their claim, I will not tell every internationally recognized chemist that they're wrong. Will you? 

We do seem to be chasing our tails. That's why I broke down your most inclusive post and disproved each point one at a time. But instead of getting a response based on the discussion, I got this: 



legallyflying said:


> This thread is a great example of why I spend little time on this site anymore.
> You try to help out but then inevitably you spend your time trying to convince some douche nozzle the realities of the situation. Woodsman is an extremely experienced grower who knows his shit front and back and yet douche #4,567 --Mike91sir feels the need to line by line debate him on the information that in my experience is accurate and correct.
> Allow me to summarize the results of the test for those that can't seem to get a grasp on things..
> 
> ...


He even said it was in HIS experience. My points are based on the experience of thousands of government-funded scientific studies. 

Instead of both of you worrying about telling me to leave to find information that supports your THEORY, why don't you both spend a couple days reading some physics/chemistry references from a library and come back and tell me HOW you can PROVE that I'm wrong. Evidence is the basis for all scientific fact, and neither of you have given me any. Despite the numerous pieces of actual scientific evidence based I've brought into this discussion, I'm still just the asshole who won't shut up, right?


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## mike91sr (Jan 30, 2012)

And just to get this out of the way since google is such a reliable method of research, here's 3 of my first google hits

http://antoine.frostburg.edu/chem/senese/101/solutions/faq/predicting-DO.shtml First sentence
http://www.colby.edu/chemistry/CH331/O2 Solubility.html Where do you choose which size bubble you have?
http://kamland.lbl.gov/twiki/pub/Main/MuonSpallationTargetMatrix/jpcrd219.pdf page 166

You can find info to support whatever theory you want on the internet. It doesn't mean it's all true. Just look at this website. Don't even leave this thread, you'll find plenty of false info right here.

Edit: Here's one that even goes as far as talking about bubble size:
http://www.fao.org/docrep/X5744E/x5744e0m.htm#2. aeration devices for fish ponds
*3.1 Oxygen Absorption and its Devices*

In order to minimize oxygen consumption devices are needed which ensure the most perfect absorption of oxygen. The operating principle of these is the same as that of aeration devices, but in order to increase the *contact time* between the gas and the water some technical modifications are needed.
One is bubbling oxygenation where the oxygen gas comes in contact with the water by breaking into bubbles. *The rate of oxygen dilution depends mainly on the depth of the water layer, the length of travel of bubbles in the water body and the rate of oxygen feeding*. *Higher efficiency can be achieved by decreasing the bubble size, thus the contact time and the contact surface increases. But the decrease of bubble size needs a significant quantity of extra energy, and coagulation of bubbles also can happen.* 

This says NOTHING about increasing the total amount of oxygen absorption, only the RATE at which it is absorbed. Just to make sure this article doesn't get misinterpreted.


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## legallyflying (Jan 30, 2012)

I fucking told you he would come back and say nuh uh!!! 

Soo classic. Comical. Troll is as troll does. So easy to rattle his cage though. Kind of fun.


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## legallyflying (Jan 30, 2012)

Hey pet flora. One thing the measuring I completed did prove is that if your only aerating your rez, all you really need is el cheapo stone. BUT if you don't want it to clog, I would pick up an alita stone. If your making a bubble cloner than yeah the more and smaller bubbles would be best, not because of oxygen but because more bubbles popping in the surface would do a better job of keeping your stems wet.


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## mike91sr (Jan 31, 2012)

You guys are so cute together kiss-ass


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## 0000007 (Feb 1, 2012)

Have you tried these yet? They have suction cups that allow you to mount them in place.
http://www.hugeharvest.com/Product.aspx?ProdID=439
http://youtu.be/srJux2cPW50
View attachment 2033362


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## woodsmaneh! (Feb 1, 2012)

0000007 said:


> Have you tried these yet? They have suction cups that allow you to mount them in place.
> http://www.hugeharvest.com/Product.aspx?ProdID=439
> http://youtu.be/srJux2cPW50
> View attachment 2033362


I have tried a similar round air stone and was not to happy with then I still have 3 new ones. May have just been the brand but since I found the fine bubble flexair I'm happy. Always looking for better ways thanks for posting.


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## Gigaah (Feb 1, 2012)

It kind of looks like no matter what stone you use. Give the margin of error. They are pretty close to the same. Probably because we are bumping up against the "maximum dissolved oxygen concentration" limit I'm assuming? 
http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm

You can "supersaturate" the water beyond those levels but I don't think you can do so by "normal" means such as air stones/agitation.


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## woodsmaneh! (Feb 2, 2012)

Gigaah said:


> It kind of looks like no matter what stone you use. Give the margin of error. They are pretty close to the same. Probably because we are bumping up against the "maximum dissolved oxygen concentration" limit I'm assuming?
> http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm
> 
> You can "supersaturate" the water beyond those levels but I don't think you can do so by "normal" means such as air stones/agitation.



I don't agree, that's the purpose of this thread is to see what the difference is. With all that has been said I don't know how you can come to that conclusion? All bubbles are not created equal. As temprature has a direct effect on DO the max depends on temp and avalible oxygen. The fact is, too much oxygen can harm plants but you need special equipment as you mentioned.


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## mike91sr (Feb 2, 2012)

Gigaah said:


> It kind of looks like no matter what stone you use. Give the margin of error. They are pretty close to the same. Probably because we are bumping up against the "maximum dissolved oxygen concentration" limit I'm assuming?
> http://www.dnr.mo.gov/env/esp/wqm/DOSaturationTable.htm
> 
> You can "supersaturate" the water beyond those levels but I don't think you can do so by "normal" means such as air stones/agitation.


Yes, these stones all performed damn near exactly the same. Sure as hell not enough to make a difference in any system. Water temperature, air pump size, and atmospheric pressure are the only things affecting your total dissolved oxygen levels and total airflow/rootzone oxygenation, not bubble size. Though smaller bubble will oxygenate your water slightly faster. But the water shouldn't ever be without aeration anyway, so this makes no difference whatsoever.


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## woodsmaneh! (Feb 2, 2012)

mike91sr said:


> Yes, these stones all performed damn near exactly the same. Sure as hell not enough to make a difference in any system. Water temperature, air pump size, and atmospheric pressure are the only things affecting your total dissolved oxygen levels and total airflow/rootzone oxygenation, *not bubble size*. *Though smaller bubble will oxygenate your water slightly faster*. But the water shouldn't ever be without aeration anyway, so this makes no difference whatsoever.


You are just so confused, and have no idea what your saying.


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## mike91sr (Feb 2, 2012)

Nice picture. Very helpful in proving my point (you have no proof to back up your ridiculous claims) Are you going to do anything besides attack me, like....I dont know.....PROVE IT? You've been asking for it for several pages now, yet all I see from you is your own theories and experiences being touted as substantiated claims with scientific proof to back it....so where is it?

Staying on topic, something neither of you seem to be able to do. Is it because you have no rebuttal to defend yourself against someone who brings proof to an argument? oooh noooo.

http://www.citycollegiate.com/chapter3d.htm
http://learningcenter.unc.edu/services/handouts/study/Guides/Chemistry 102/Factors Affecting Solubility
http://chem.wisc.edu/deptfiles/genchem/sstutorial/Text11/Tx112/tx112.html
http://en.wikipedia.org/wiki/Solubility#Solubility_of_gases
http://www.saskschools.ca/curr_content/chem30_05/4_solutions/solution1_3.htm
http://www.solubilityofthings.com/basics/factors_affecting_solubility.php I know it says molecular size and you're going to try to say it means bubble size, but lets be sensible here. Bubbles of any size still have the same size molecules, unless you learned how to change the composition and structure of oxygen via airstones?


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## woodsmaneh! (Feb 2, 2012)

you said it yourself "smaller bubbles oxygenate the water better" that's what we have been saying all along, Check Mate, you should let up on the smoke boy, your short term is gone...


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## jeeba (Feb 2, 2012)

I have to agree with Woodsmaneh bubble size does matter it increases the surfae area which is directly related to gas exchange at the waters surface.But I also agree with you on the temp,pumpsize.I will look for a article I read on this very subject on a Fish Health forum.Gimmie a few I will post a link if anyone is interested.


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## mike91sr (Feb 2, 2012)

Uh-oh, gas exhange at the water's surface. That's a big no no in this thread too. 

Bubble size(surface area) affects only rate of solution, not solubility. When somebody here can actually prove otherwise, I'll rip that page out of my main chemistry reference text.
Woodsman, I didn't say that. Stop putting words in my mouth. "faster" is not "better" Faster means it gets to max DO faster. Better would mean it gets to a higher ppm, but it doesnt. Keep your shit straight if youre going to falsely try and tell me to do the same


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## jeeba (Feb 2, 2012)

http://edis.ifas.ufl.edu/ss525 Not what I was talking about but a good read on dissolved oxygen.One thing I read is that water has a low D.O it is oxygenated faster than water with a higher D.O,Im not trying to become part of the argument,trying to have a discussion,and possibly learn something.I will still look for the other information.As opposed to post whoring I will edit this info in.Taken from the Koiphen Forums. "When air is in contact with water, oxygen will enter the water from the air until the pressure of the oxygen in the water is equal to the pressure of the oxygen in the air. Oxygen must enter or leave a body of water at the air-water interface, so for the very thin film of water in contact with air the greater the oxygen deficit or oxygen surplus , the faster oxygen will enter or leave the film. Once in equilibrium oxygen tension is the same in air and water and transfer ceases.

There are many physical and biological factors affecting dissolved oxygen concentration in water such as temperature, pressure (depth), salinity, photosynthesis and respiration amongst many.......Photosynthesis produces oxygen and respiration consumes oxygen. 

Our "closed water systems" generates enormous amounts of bio loading from plants and fish, which in turn consume large amounts of oxygen through respiration. Which is one of the reasons we always recommend aeration to near saturation in our ponds...."


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## mike91sr (Feb 2, 2012)

Theory of relativity. Einstein. It's the same as temperature changes. Two glasses of water, one is 35*, the other is 55*. Both put into room temp at 75*, the 35* water will change temperature faster. It doesn't mean it will get to 75 before the other though, as it has further to go. It also doesn't mean that it will get to 80*(take note woodsman). Once both cups are at 75*, it doesn't matter what kind of cup they're in or what the surface area is, 75* is 75* no matter how you look at it. It's not going to be any different if it took longer to get there, whether it be the extra hour it takes for the water temp in this example, or the extra 1/4 second it takes for oxygen to dissolve in water. 

My point about rate of solution vs solubility is relatively the same, that unless you are letting your water become un-oxygenated, there is no need for it to have the ability to oxygenate faster. It doesn't change the chemical properties that limit how much oxygen can be present.

I've put up about 15 links at this point, mostly to scholastic studies with measured evidence as opposed to the "I think my plants grew faster" claims found in most forums. If you read through every single one of them thoroughly (don't), you'll find ZERO mention of surface area(bubble size) in relation to solubility(DO in this case). You will however find tons of talk about its effect of rate of solution. You need to understand the difference between the two to understand why woodsman is incorrect.


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## jeeba (Feb 2, 2012)

Hey Mike why is gas exchange at the waters surface a nono?I didnt read the whole thread the bickering was a turn off and helped me to skip through some.Can you read my edited post and tell me if its true false or partially both?


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## mike91sr (Feb 2, 2012)

Good call skipping through lol, you can see where all the bickering has gotten us....

Anyway, I was mostly kidding about it being a no-no. Throwin another dog into the fight, ya know? And despite the fact that gas is in fact exchanged at the surface and is increased by turbulence and greater surface area(of water, not air bubbles), some people have argued that it's the ONLY place it happens, not in this thread. It apparently pissed off legally bad enough that years later he's still upset. It became apparent somewhere in there lol, I'm not going to look for it and its not worth your time to bother.


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## jeeba (Feb 2, 2012)

mike91sr said:


> Good call skipping through lol, you can see where all the bickering has gotten us....
> 
> Anyway, I was mostly kidding about it being a no-no. Throwin another dog into the fight, ya know? And despite the fact that gas is in fact exchanged at the surface and is increased by turbulence and greater surface area(of water, not air bubbles), some people have argued that it's the ONLY place it happens, not in this thread. It apparently pissed off legally bad enough that years later he's still upset. It became apparent somewhere in there lol, I'm not going to look for it and its not worth your time to bother.


Cool man thanks for clarifying so my understanding of it is not that flawed.


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## legallyflying (Feb 2, 2012)

You know what's funny? You constantly bumping this thread to the top with your nonsense. Whenever I log in all I see is that my latest rep count just says "quantitative airstone" from top to bottom. 

Since your the man of all things hydro, I think we should just settle this with some good old fashioned bud porn.


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## jeeba (Feb 2, 2012)

legallyflying said:


> You know what's funny? You constantly bumping this thread to the top with your nonsense. Whenever I log in all I see is that my latest rep count just says "quantitative airstone" from top to bottom.
> 
> Since your the man of all things hydro, I think we should just settle this with some good old fashioned bud porn.


Show me yours Ill show you mine?I used to play that game with girls in jr high!


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## mike91sr (Feb 2, 2012)

Here we go again lol. Anytime you want me to shut up, just prove me wrong. Until then, just worry about shipping back your top-of-the-line airstones (and your rep count)


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## legallyflying (Feb 2, 2012)

^^. I'll translate that... I've only grown a single crop and it is pitiful (most likely because I'm a hard headed tool) 
Prove me wrong! Prove it! Why don't you address this question? Cause you can't prove it? Where is the proof?


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## woodsmaneh! (Feb 2, 2012)

*Impact of bubble and free surface oxygen transfer on diffused
aeration systems
* 
_I supose you think these people don't know what they are talking about?
_ 
Connie D. DeMoyera, Erica L. Schierholza, John S. Gullivera,*,
Steven C. Wilhelmsb
a St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Mississippi River at 3rd Avenue, SE,
Minneapolis, MN 55414, USA
bUS Army Corps of Engineers Research and Development Center, Waterways Experiment Station, 3909 Halls Ferry Road,
Vicksburg, MS 39180, USA
Received 1 November 2001; received in revised form 1 November 2002

*6. Conclusions
*The standard testing methodologyfor oxygen transfer
in aerated systems oversimplifies the oxygen transfer
process and makes adjustment of measured values to
other depths intangible. This paper more accurately
describes the oxygen mass transfer process and advances
McWhirter and Hutters mass transfer model by
considering both oxygen transfer and the transfer of
other gases, primarilynitrogen, into and out of the
bubbles as theyrise to the water surface. *Model results
indicate that the surface-transfer coefficient in a 9.25m
tank with an air flow rate of 5176 scmh is 5985% of
the bubble-transfer coefficient. The analysis of the gasphase
oxygen composition and liquid-phase equilibrium
concentration shows that the bubblewater concentration
gradient is also of greater magnitude than the air
water concentration gradient.
*Experiments and analysis designed to determine the
relative location of high surface-transfer coefficients
indicate that the large transfer coefficient directlyabove
the bubble plume is related to air discharge, while the
lower transfer coefficient outside of this region is not
related to air discharge.
Surface transfer and bubblewater transfer both
contribute significantlyto the total oxygen transfer in
this type of diffused aeration system. *Bubblewater
transfer, however, is the dominant means of oxygen
transfer.* These results were obtained numerically and
verified experimentally. The results can be applied to
aerated systems at similar depths or to deeper water
systems where the higher bubblewater concentration
gradient near the submerged diffuser should cause an
even greater dominance of bubble transfer in the
aeration process. I*nsight into the relative importance
of transfer across the water surface and bubble surface
can be used to design more effective diffused aeration
systems for lakes, reservoirs, and wastewater treatment
facilities at a varietyof water depths.
*Acknowledgements
*The experiments described and data presented, unless
otherwise noted, were part of research conducted under
authoritygiven bythe US ArmyCorps of Engineers
DistrictChicago. Permission was granted bythe Chief
of Engineers to publish this information. *The authors
thank Jian Peng and Miki Hondzo for their conceptual
input into this research and their helpfulness in
conducting aeration tests. We also thank Calvin Buie
and Jason Giovannettone for assisting with aeration
experiments during hot Julyday s in Mississippi.
References
[1] Fischer HB, List JE, Koh RCY, Imberger J, Brooks NH.
Mixing in inland and coastal waters. San Diego: Academic
Press, 1979.
[2] Popel HJ, Wagner M. Modeling of oxygen transfer in deep
diffused-aeration tanks and comparison with full-scale
plant data. Water Sci Tech 1994;30(4):7180.
[3] McWhirter JR, Hutter JC. Improved oxygen mass transfer
modeling for diffused/subsurface aeration systems. AIChE
J 1989;35(9):152734.
[4] American Societyof Civil Engineers. Standard for the
measurement of oxygen transfer in clean water. New York,
NY: ASCE, 1992.
[5] Neilson BJ. Reaeration dynamics of reservoir destratification.
AWWA J 1974;66(10):61720.
[6] Camp TR. Water and its impurities, 2nd ed. New York:
Reinhold Publishing Corp., 1963. p. 335.
[7] Holroyd A, Parker HB. Investigations on the dynamics of
aeration. J. Inst. of Sewage Purification 1949;3:292.
[8] Wilhelms SC, Martin SK. Gas transfer in diffused bubble
plumes. In Jenning SM and Bhowmilk NG, Eds.
Hydraulic Engineering: saving a threatened resource-in
search of solutions. ASCE, New York.
[9] Scouller WD, Watson W. Solution of oxygen from air
bubbles. Surveyor 1934;86(2215):156.
[10] Higbie R. The rate of absorption of a pure gas into a still
liquid during short periods of exposure. Am Inst Chem
Eng 1935;31:36589.
[11] Coppock PD, Meiklejohn GT. The behavior of gas
bubbles in relation to mass transfer. Trans Inst Chem
Eng 1951;29:75.
[12] Ippen AT, Campbell LG, Carver CE. The determination
of oxygen absorption in aeration processes. Mass Inst
Technol Hydrodyn Lab Tech Rep 1952;7.
[13] Pasveer A. Oxygenation of water with air bubbles. Sewage
Ind Wastes 1955;27:113046.
[14] Calderbank PH, Moo-Young MB. The continuous phase
heat and mass-transfer properties of dispersions. Chem
Eng Sci 1961;16:3954.

The full report is here

http://144.206.159.178/FT/1092/86893/1471661.pdf


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## woodsmaneh! (Feb 2, 2012)

Mike91 I'm not a weekend grower, I take my growing very serious and go to great lengths to make sure what I do is founded in science and reasearch. Knowing a little about something does not make then an expert, you need to look at the big picture and if smaller bubbles work better than I will keep tweeking my systems till I get the biggest plant I can grow. So in an effort to be the best I can I will apply every thing I learn to that end. Big gains are very hard to get but running a ideal grow enviorment and makeing sure every aspect is as good as it can be = 1# plus plants.

Some people are happy just tossing things together or just doing what everyone else does, someone needs to lead and it's guys like leagllyflying, ucundercurrent and me who try to do that, intresting thing is not maney people can help us as were the leading edge of growing in water so we try to advance the cause by shairing. So if you still got your nickers in a knot lets agree to disagree and get back to the work at hand.


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## woodsmaneh! (Feb 2, 2012)

http://techalive.mtu.edu/

https://www.rollitup.org/index.htmhttps://www.rollitup.org/Glossary.htmhttp://techalive.mtu.edu/support/











 https://www.rollitup.org/HypolimneticOxygenData.htm[h=1]Oxygen Mass Transfer[/h]https://www.rollitup.org/OxygenTransferRate.htm










The rate of oxygen mass transfer , i.e. from the gas (air bubbles) to the liquid phase (water) is governed by the terms described below. Typically, K[SUB]L[/SUB] and a are combined into an overall mass transfer coefficient
(K[SUB]L[/SUB] a, d[SUP]-1[/SUP]). 
​ 



​​ K[SUB]L[/SUB]
liquid film transfer coefficient for oxygen (md[SUP]-1[/SUP])
a
the ratio of bubble surface area to water volume (m[SUP]-1[/SUP])
(C[SUB]s[/SUB] - C)
the oxygen deficit (gm[SUP]-3[/SUP]) 
https://www.rollitup.org/Glossary.htm#avratio 







 
http://techalive.mtu.edu/modules/module0001_alt/OxygenMassTransfer.htm


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## woodsmaneh! (Feb 2, 2012)

Area to Volume Ratio The specific interfacial area available for mass transfer (a, m1) is expressed as the ratio of the bubble surface interfacial area (A, m2) to water volume (V, m3), Small bubbles afford greater surface area and lead to more efficient gas transfer, e.g. 1m3 of bubbles with a 1 cm diameter have 10 times the surface area of 1m3 with a 0.1 cm diameter. Thus bubble size is a feature of diffuser design. So I guess you can saddle up and ride into the sun set never to be seen again, The lesson her folks is just because your persistant in your views does not make them right, I got to build my knowlage base and prove what I was saying, so was worth it.So more rep for me and a big Zero for you and I would question anything you might have to say in the future...... Go read that book of yours but make sure it's right side up.


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## legallyflying (Feb 2, 2012)

Well said sir. 

Woodsy, I think the excitement level over the new UC system is actually making my clones root out slowly. Somehow they know I can't wait to stick them in the new system. 

And of course...my buddy says "hold off dude, I can cuttings of a dank ass c99". And I just got super skunk seeds in, sprouted another round of super skunk, and just ordered some double barrel OG from dank house. 

At any rate, I'm going to post pictures of the "space station 2000" tonight over on that other (less douche bag) forum


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## woodsmaneh! (Feb 2, 2012)

The oxygen deficit (D) is the driving force for the establishment of air-water equilibria and is calculated as the departure from saturation: The saturation concentration for oxygen is calculated using Henry's Law and varies with temperature (effect on K[SUB]H[/SUB]) and P[SUB]O2[/SUB], the partial pressure of oxygen.


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## jeeba (Feb 2, 2012)

woodsmaneh! said:


> Mike91 I'm not a weekend grower, I take my growing very serious and go to great lengths to make sure what I do is founded in science and reasearch. Knowing a little about something does not make then an expert, you need to look at the big picture and if smaller bubbles work better than I will keep tweeking my systems till I get the biggest plant I can grow. So in an effort to be the best I can I will apply every thing I learn to that end. Big gains are very hard to get but running a ideal grow enviorment and makeing sure every aspect is as good as it can be = 1# plus plants.
> 
> Some people are happy just tossing things together or just doing what everyone else does, someone needs to lead and it's guys like leagllyflying, ucundercurrent and me who try to do that, intresting thing is not maney people can help us as were the leading edge of growing in water so we try to advance the cause by shairing. So if you still got your nickers in a knot lets agree to disagree and get back to the work at hand.


This is the kind of things Im interested in and the post b4 that woulda seemed alot classier without the dude are you that fucking stupid jpeg.What I got out of it is that when the bubble exits the airstone it creates another"surface" to exchange gas?Like say the top of the pond, lake ,bucket,res?If Im wrong please feel free to correct my assumption.I welcome it. Thanks


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## mike91sr (Feb 2, 2012)

woodsmaneh! said:


> Mike91 I'm not a weekend grower, I take my growing very serious and go to great lengths to make sure what I do is founded in science and reasearch. Knowing a little about something does not make then an expert, you need to look at the big picture and if smaller bubbles work better than I will keep tweeking my systems till I get the biggest plant I can grow. So in an effort to be the best I can I will apply every thing I learn to that end. Big gains are very hard to get but running a ideal grow enviorment and makeing sure every aspect is as good as it can be = 1# plus plants.
> 
> Some people are happy just tossing things together or just doing what everyone else does, someone needs to lead and it's guys like leagllyflying, ucundercurrent and me who try to do that, intresting thing is not maney people can help us as were the leading edge of growing in water so we try to advance the cause by shairing. So if you still got your nickers in a knot lets agree to disagree and get back to the work at hand.


I'm not sure where you thought I said I was an expert grower, but all I'm doing is standing by the facts that have been known for some time about chemical and physical properties, not even grow-related info. I gave both of you the respect to even come out and say you're more experienced, knowledgeable, and skilled growers, yet somehow I'm still catching shit from both of you about acting like a know-it-all. Nowhere on this board am I dropping my opinion as fact or claiming to be some awesome grower. I'm on my first hydroponic grow, and freely advertise it. That doesn't change the fact that I have substantial knowledge from other realms that do not change just because it's now related to a plant I have little experience with. And nowhere did I claim anything besides that. I was honestly under the impression you and I were having a halfway decent debate about something of a technical nature(which, don't worry, I'll get to in a sec), and then out of nowhere I started getting slammed by legally for not just shutting up and doing as you were telling me. By the time you came back into it, of course it had reached a personal level. I respect your drive to constantly learn and improve, and have learned immensely from it myself, but when I see something that is factually incorrect, I'm going to call it. My posts, while sometimes abrasive and not necessarily justified to say the least, still managed to keep more of a technical nature than either of yours towards me. Look at the the last page. You answered somebody, I did the same, and from then on, every post from you and legally is a direct attack against me. How useful is that? 

Now, like you said, back to work. If you're going to get pissed that I feel like you and I should continue the debate that was the cause of all this,let me know, but for now, I'm going to continue clearing this up. I dont care if legally continues to do nothing but slam me all day long, if you can be decent towards me, I'll return the favor.

You are mixing up two very similar terms and it's the difference between the two that makes your theory false. Your last post proves my point, not yours:



woodsmaneh! said:


> The *rate of oxygen mass transfer* , i.e. from the gas (air bubbles) to the liquid phase (water) is governed by the terms described below. Typically, K[SUB]L[/SUB] and a are combined into an overall mass transfer coefficient
> (K[SUB]L[/SUB] a, d[SUP]-1[/SUP]).​​ 



From the same website:
"The saturation concentration for oxygen is calculated using Henry's Law and varies with temperature (effect on K[SUB]H[/SUB]) and P[SUB]O2[/SUB], the partial pressure of oxygen."

Edit: you posted it yourself. Do you know what Henry's Law is, and how it proves your theory wrong?


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## mike91sr (Feb 2, 2012)

woodsmaneh! said:


> Small bubbles afford greater surface area and lead to more efficient gas transfer, e.g. 1m3 of bubbles with a 1 cm diameter have 10 times the surface area of 1m3 with a 0.1 cm diameter.


K, then I saw this post...
More efficient does not mean that more can be transferred. Please tell me you understand this. If you do, it means you understand that bubble size makes no difference in how much oxygen is available in the water. Like you said, being persistent doesn't make you right.


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## mike91sr (Feb 2, 2012)

jeeba said:


> This is the kind of things Im interested in and the post b4 that woulda seemed alot classier without the dude are you that fucking stupid jpeg.What I got out of it is that when the bubble exits the airstone it creates another"surface" to exchange gas?Like say the top of the pond, lake ,bucket,res?If Im wrong please feel free to correct my assumption.I welcome it. Thanks


Yes, and because it's rising, it comes into contact with more h2o. More surface area will mean it can exchange faster, not that any more can be exchanged. This difference being misunderstood is the only reason this argument is still going on. More total air(not the same amount of air split up differently) will mean there's more air to be exchanged. More total air comes from a bigger pump, plain as that.


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## jeeba (Feb 2, 2012)

mike91sr said:


> Yes, and because it's rising, it comes into contact with more h2o, making it more efficient than just having the surface area sitting stagnant. More surface area will mean it can exchange faster, not that any more can be exchanged. This difference being misunderstood is the only reason this argument is still going on. More total air(not the same amount of air split up differently) will mean there's more air to be exchanged. More total air comes from a bigger pump, plain as that.


This being said I believe the size and dissapation amount of the airstone is directly related to the size and flow of the pump you are using?When I use my epdm airstone utilizing a single outlet from 80 lpm pump it is overpowered and makes huge bubbles.As opposed to 8 2 inch airstones all diffusing small bubbles.You can see it moving more area through the coloumn,Get my drift?


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## legallyflying (Feb 2, 2012)

mike91sr said:


> Yes, and because it's rising, it comes into contact with more h2o. More surface area will mean it can exchange faster, not that any more can be exchanged. This difference being misunderstood is the only reason this argument is still going on. More total air(not the same amount of air split up differently) will mean there's more air to be exchanged. More total air comes from a bigger pump, plain as that.


Ok,k honestly, this is the last time I am going to address this. And seriously dude, and I don't mean this in an insulting way although it is getting quite fucking annoying at this point, your just clinging onto this whole notion that rate of transfer and total transfer are completely independent of each other in this application and they are not. 

Obviously the principal understanding in all of this is that max DO has not been reached... because no bubbles are going to surpass the max DO level. SO STOP SAYING it doesn't equal more, it doesn't equal more because you can't change the maximum level of oxygen in solution (DO). (ALTHOUGH, everyone should realize by now that it is NOT JUST DO levels that will effect plant growth. Bubbles passing over the roots will increase oxygen (and mineral) uptake. 

1. more surface area DOES equal increased quantity of gas exchanged. The exchange RATE is total transfer/ time. Given the same amount of time (the time it takes for bubbles to rise to the surface) MORE air will be transferred. This is especially true since the smaller bubbles will have more time in water since they do in fact travel to the surface slower. So you are increasing the time that transfer is occurring. 

It is quite simple that as long as the water is not already at max DO levels, that a faster rate of transfer will equal more transfer. 

It is well documented in the aquaculture, and to a greater extent, the sewage treatment industry that small bubbles are the MOST EFFICIENT means to oygenate water. PERIOD. END OF STORY. Given a particular amount of energy to produce and distribute the air (like watts of pump or HP), small bubbles will more effectively oxygenate the water. Don't get all side tracked on the notion that faster does not equal more. There is plenty of literature in the waste treatment world that will say the same thing. Smaller bubbles equal more efficient transfer. Which means MORE oxygen put into solution, not just faster which you claim. 

Lastly, given the different efficiencies of different sized bubbles, you can not state that more total air will equal more transfer. This again comes back to the small bubbles being the more efficient. So while yes, at some point simply pumping more air through a large bubble stone will surpass the amount of air transferred from a small bubble stone and smaller pump, you can just say that a bigger pump is better "plain as that". Actually, ignoring the benefits of bubble to root air exchange, a bigger pump is just a waste of money as you could get the same QUANTITY of exchange with a smaller pump and smaller bubbles...as that is what MORE EFFICIENT MEANS.

http://www.processenergy.com/Aeration Paper.pdf

Look at table 1 in that link. It says it all. The faster RATE of transfer equals MORE TRANSFER per energy unit/time. So again, a faster transfer DOES mean more transfer.


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## mike91sr (Feb 2, 2012)

@ jeeba: Ultimately, h2o can only hold so many extra oxygen atoms in solution (bar supersaturation). So the stone has no actual effect on total dissolution, that's what the experiment proved. The reason there is now confusion is because legally and woodsman are saying that the stone DOES make a difference(due to bubbles being smaller). Providing max DO in a container, as proven, can be done with a relatively small pump and just about any stone. To get more oxygen to the roots you then need a bigger pump not a different stone, unless the stone has a max airflow rating lower than the pump's. It's no longer an attempt at dissolving more oxygen, but creating a constant supply of air pockets (bubbles) around the roots themselves. Think of an aeroponic system. The roots get oxygen primarily from their surrounding air, not DO. Once max DO is reached, that's it. Providing more air flow only changes how much volume of undissolved air is present for the plants. More undissolved air is a good thing, it's just not caused by stone "upgrades", and I need to make sure that's clear.

Think of it this way: If a garbage bag can hold 50lb of baseballs before it rips, does it matter if the baseballs are whole or cut into halves or quarters? No, they're still going to weigh the same amount, and ultimately, the bag will not get stronger just because the baseballs are now smaller. 

Likewise, if a factory can produce 20 baseballs per minute (pump's airflow), it doesn't matter if they ship them in 10 trucks of 1000 or 1 truck of 10000 (surface area of bubbles). They're still only going to produce 20 baseballs per minute. It's faster to unload 10 trucks of 1000 because you can have more access to the baseballs and therefore more work being done at once, but in our case this makes no difference as the supply of bubbles (baseballs) is constant regardless and we only have so much space to keep the baseballs (DO being maxed out). So even though they can work faster, they don't, there's no change because speed of dissolution, or unloading the trucks, was never a factor..

The diffuser should have smaller bubbles unless they're coagulating. I'm honestly unsure about the conditions required for that to happen, though I read through something yesterday that talked about it. I'll try and find it again. Ultimately, my point remains same: Your 80lpm pump, whether hooked up to 1 epdm stone or 1 blue stone, will provide roughly the same amount of airflow, provided that the stones' max airflow is at least 80lpm and their resistance to flow is similar. Legally said his diffusers were more restrictive, so the diffusers will actually flower less air, probably not any substantial amount though. I can't find specs on the cheaper stones otherwise I'd be able to have a definitive downside of diffusers. But you can see a very clear difference in total water turbulence when running the blue stones over the diffusers, due to a less restrictive flow of air. Regardless, I have 10 buckets to aerate, so for me to max out the airflow(not DO) of 10 airstones will take a lot more air pump capacity than I care to have no matter what stone they are. And no matter what stone they are, DO will be the same. Resistance to flow is more important than bubble size, as this will affect how much air can be constantly present for the plants vs bubble size which affects only the rate of solution(irrelevant here).

If, however, I upgrade and have 5x250lpm pumps and my stones can only flow half of that, yes a stone add-on or upgrade may be warranted. But not even to a diffuser, as legally said himself that they were more restrictive. Larger or more stones would do the same thing. And again, that won't change DO(which was already maxed out), but will provide more total airflow to the plants. Because more oxygen (not dissolved) will be present, and more oxygen is generally better, the plants will then benefit. 

Moral? Pump upgrades are more important than stone upgrades, unless you already maxed out your stone's airflow. To check this on a 2+ outlet pump, close one outlet and see if the airflow on the other changes. If it does, your pump is not able to push as much as as the stones are able to flow. If it doesn't, you may want to look into stones that allow for more airflow. That way, your pump and stone capacity is about equal.


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## mike91sr (Feb 2, 2012)

Thank you for at least trying to post a bit of info and not just slamming me personally based on your growing experience vs my scientific evidence, and I'm fine if you no longer address my posts, however yours still have several flaws (including that link) that I'm going to point out, and then let you think whatever you like because, clearly, none of us is going to budge. But honestly, there was no need for any of the bs this thread is now filled with. Your write-up was great and I originally just wanted clarification as to why you started believing things that went against it, thinking maybe there was something I was missing. There wasn't, and you shelled out pages and pages of nonsense at me for not backing down, responding to my on-subject posts to OTHER PEOPLE with your own slandering. I understand its your thread, but at least have the decency, for other readers finding this thread, to explain why you think I'm wrong. Until now, you really did very little of that, and instead made it known that you dislike people who don't accept disproven theories over proven facts. Just check out post #21 and your response, #23. A simple question about the application and validity of the test, and actually, a question that you still haven't answer correctly in this thread. Then, #28, you state very similar things to what I'm not saying, yet you're willing to try and bash me for standing by it now. It was the same thing 18 pages ago, if someone questions you, you go off the handle before anything else, then MAYBE, get around to attempting to provide something useful. which, youre still defending the theory that is applied in a stone you yourself are sending back....??? You cant get upset if people don't want to just take your word for everything when every other time someone questions your word if your response is telling them youre not going to spend the time to fix a flaw or void in the test. Doesn't build much credibility for defending your theories when you're able and not willing to test them. Which is fine, but like I said just dont get upset when people still call bs.

1. Solubility and rate of solution ARE two different things and neither is affected by the other whatsoever. Stirring a solution increases rate of solution. Stirring also generally decreases solubility. A higher temperature increases rate of solution. A higher temperature, in the case of a gas, decreases solubility. Think hot soda bottle exploding. See my point? Henry's Law and the Combined Gas Law are fundamental principles that have withstood decades of testing, and those two theories are all I really need to prove my point, but here goes anyway.


2. You seem to be ignoring the fact that I agree, smaller bubbles=more EFFICIENT transfer, given that efficiency=work/time. BUT,having the ability to be more efficient does NOT mean that you got more work done. An h2o molecule isn't going to hold more oxygen just because it has more time to do it. This fact cannot be disputed. So faster does necessarily not equal more if the AMOUNT is limited. Driving 100mph won't get you any further than 25mph if you only have one tank of gas, but you'll get there faster. It's still only one car showing up at the same spot though, same end result. Right? 


3. I never stated that more airflow=more DO. I said that more airflow=more *UN*dissolved oxygen in an environment where DO is maxed, which is also a good thing. Do we agree here? Because max DO can be reached fairly easily at a given temp(your statement, not mine), what's the point of smaller bubbles allowing "faster" transfer of a gas that is already at its full capacity in the solution? In the case of SWC or something of that nature where the oxygen must be quickly absorbed given the shorter timeframe from stone to surface, yes, smaller bubbles with greater total surface area resulting in faster absorption would be more effective because TIME is the limiting factor, not max amount. However, that is NOT a factor in most applications, including ours. It's not going to dissolve more of anything just because it can dissolve faster if it's already maxed out, simple as that.


4. Yes, the bubbles travel slower, providing more time for dissolution, and with a greater surface area, the ability to be more efficient. And up front, that seems to be all there is too it, like you're trying to tell me. But there is more; More oxygen will *not* be transferred. So the "amount" part of that equation will remain the same. If this weren't true, the diffusers would have shown a higher DO in your test. 

Hypothetical numbers: 50 atoms of oxygen/minute can be dissolved with diffusers. 25 atoms of oxygen/minute can be dissolved with blue stones. Because water can only absorb <25 atoms of oxygen/minute, that benefit is not seen here. I say that less than 25 atoms/minute can be dissolved with water because all I really know is that it* IS* in fact less than the blue stones can provide. Again, if this weren't true, the diffusers would have shown a higher DO in your test.


6. What it comes down to is that h2o only allows so much oxygen to be dissolved, the rest will be passed over the roots, then onto the surface. You seem to be forgetting that the rate of solution doesn't matter if no (or very little) dissolution is happening, as time is not the limiting factor here but capacity. Because time is not a limiting factor here, neither is the size of the bubbles. Though it could be in other situations, such as waste treatment like you said(I honestly don't know anything about their processes, environment, etc.)

7. If I was wrong, the diffuser's ability to create smaller bubbles and therefore allow for faster dissolution would have resulted in an increase DO. But because the DO wasn't increased, the rate of solution clearly has no effect on how much ends up being dissolved(solubility). It all adds up to this, and I'm not sure why you still insist on arguing the very facts that build the foundation to prove your original write-up CORRECT, and current/changed beliefs to be INCORRECT.


Now, I'll leave this discussion be, as all I can do is provide the info with proof, I can't force anyone to accept it. I think I did a good job of getting enough outside reading and substantiated fact into this thread that people can make their own informed decision. But if you respond to my post to tell me I'm wrong, I'm not going to NOT defend myself. Hence the ongoing argument. Otherwise, Im gonna go on smoking my pitiful harvest and tending to my shitty grows. happy growing


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## legallyflying (Feb 2, 2012)

I like turtles


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## Gigaah (Feb 2, 2012)

Good point Leagallyflying. While while bubbler methods appears to me to easily cap out the max DO of the water. The bubbles themselves actually interface with the roots. So that has to be taken into account. I'm now here near an expert.I'm just looking at what I can grasp


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## legallyflying (Feb 2, 2012)

Giggah, that is probably the most important part of the whole deal. I cant think of a way to test that aspect though. After having several cheap stones clog up and areas of huge root balls that were not growing anymore because of no bubble coverage I decided that coverage and ability to remain clog free were the most important. The flexair discs are huge and put out small bubbles but were not working at the psi I was running. So I ended up with the 12" alita airstones


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## Illegal Smile (Feb 3, 2012)

I have double Boss Hog air diffusers and I wouldn't trade them for anything.


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## CaliMackdaddy (Feb 3, 2012)

Illegal Smile said:


> I have double Boss Hog air diffusers and I wouldn't trade them for anything.


Seems rather expensive for an air stone, 50 bucks? Really...


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## legallyflying (Feb 3, 2012)

CaliMackdaddy said:


> Seems rather expensive for an air stone, 50 bucks? Really...


word... and the one micro diffuser I have clogs


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## SmokinLabrador (Jul 4, 2012)

So did anyone ever figure out a pump to happily push 4 of the 9 inch disks? Looking to piece together some buckets, and that disk looks perfect.


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## SmokinLabrador (Jul 5, 2012)

Figured I would follow up my own post. Got one of the retailers of the disc on the line, and to put the disc to its upper limit pump wise, you need to be in the neighborhood of 141 lpm PER DISC. Legallyflying, this would explain why pushing 4 of them with 110 lpm didn't do much. You would need to be around 560-570 lpm to give those things a workout.


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## sawyer (Dec 29, 2012)

legallyflying,

did you ever do a 'control' measurement where you measured the DO of the water without any airstones? I'm curious to know what the 'control' DO values are compared to the aerated values.

btw I've read some of your other threads. good stuff bro. thanks for all your hard work


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## joker0020 (Dec 29, 2012)

great info thanks


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## legallyflying (Dec 29, 2012)

I thought I did a control. Would be weird if I didn't. I switched out my undercurrent system for DWC. The 12" alita stones don't fit in the buckets so I am back to using the 2" round stones. May upgrade all the buckets to alita stones in the future. They are VERY nice and never seem to clog. 

In other news, I upgraded to the pond master pumps off eBay (look like alita) an they are fantastic !!!!


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## rhaven (Jan 10, 2013)

to measure the amount of air present in bubbles you could measure the increase in volume when the pump is turned on. The bubbles make this harder by making the surface rough so you'd probably want to measure the level in a side tube without bubbles in it. The best test would of course be to grow a large number of clones in as close to identical conditions as possible except different air stones, but I bet you'd need a huge number of clones to observe a statistically significant difference other than from clogging rate.


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## legallyflying (Jan 11, 2013)

It's not the amount of air.. that is easy its printed on the pump. It is the effeciency of air transfer to the water by different sized bubbles and the degree of turbulance. 

Or I could just use the round sintered stones and forget about all the jazz


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## FThat (Jan 11, 2013)

Hey guys. I'm new around here and I have always used the 6" blue air stones. They seemed to work better then the straight ones for me in my 4 gal DWC's. 

That being said. I am going to go to a larger reservoir soon and will be buying one of these.

I watched a video on Youtube about the Venturi effect and this looks like a good way to keep nutrients from settling and also blast some serious air into the water. A lot of people use this style pump for fish ponds because they work so well. 

Anyways, I just wanted to pass off some info and hopefully this pump will work in my reservoir better then the air pump and stone method. 

[video=youtube_share;2OwSfebg-TI]http://youtu.be/2OwSfebg-TI[/video]


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## Sativied (Feb 2, 2013)

Sounds like marketing bs (regarding to the pump above), for $22 I'd be surprised if it works better, but sure would have been nice to get some measurements with this one considering the price. Did you buy it yet and do you use it already?

If anyone is going to test again, I'd be very interested in the DO in a rez in which return water drops/falls from 10" into the rez, for example in an Aeroflo-like or NFT system, and whether that would add something to using air pump + bubble stones. 

If I ever get one of those meters I want to try some different types of waterfalls for the return water. I got a water dispenser sort of thing for my cat, it's basically the top half of a sphere with a small pump inside that pumps the water through the center to the top which then surrounds the sphere with a thin waterfall. Not sure how effective that is, probably more about keeping it to a minimum level than adding oxygen, but it significantly reduces the sound as well. If I place the top half of the sphere about half an inch below the return exit, and still half it a few inches above the water level in the rez, I could have a thin hollow cylinder of water drop back in the rez.


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## hotrodharley (Feb 2, 2013)

Aeration by waterfall is the most commonly used aeration technique overall for enclosed water sites like aquaculture. Yes I know people use aeration equipment directly into the water. But water falling through the atmosphere is well aerated if the fall is adequate. Roiling water where the flow enters is a sign you have enough flow to aerate at least that area of your water. I used an evaporative cooler pump - waterfall system to aerate a 500 gallon stock tank I had put crawdads in. Never encountered an oxygen problem, just an acute buildup of nitrogenous waste that was not adequately disposed of by replacing 1/4 of the water volume daily per LSU.


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## Sativied (Feb 2, 2013)

hotrodharley said:


> But water falling through the atmosphere is well aerated if the fall is adequate.


The thing I'd like to know/measure in particular is the difference between the effect of creating max roiling opposed to spreading the waterfall as thin as possible to increase it's surface area while falling (also spreading the coiling, not sure what that does with the coiling total, I'd guess make it less and quieter).

In my case the water pump timer settings would play a huge role as well, for example during night time if it sprays less often with longer intervals between it.... not going to work, unless I use a small water pump just to create the waterfall. Which would raise a waterfall through water pump vs air pump +bubble stones question.


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## hotrodharley (Feb 3, 2013)

I think obviously the thinner the sheet of the fall the greater the ability of the water to absorb O2. Oxygen is a very friendly molecule and likes to attach itself to another O molecule or a myriad of other elements. The folks at LSU that helped me long distance were the ones who proposed the waterfall for aeration. Along with replacing 1/4 of the total volume daily. They advised against a greater change due to pH and O2. Didn't quite work. We had to eat over 200# of crawdads that night. People got gunny sacks full dropped anonymously at their doorstep.


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## Sativied (Feb 3, 2013)

hotrodharley said:


> I think obviously the thinner the sheet of the fall the greater the ability of the water to absorb O2. Oxygen is a very friendly molecule and likes to attach itself to another O molecule or a myriad of other elements.


Thanks for educating me on that - I should have paid more attention in physics class. Makes sense though. Would it still need an air pump because it's enclosed? With the bubbles the water touches fresh air, with just a waterfall...

Made some pics of the pet water dispenser thingy I mentioned earlier. The flower-shaped thing at the top happens to fit up side down, with some minor work, in my return hose, first splitting the stream in six before spreading it over the flower. Obviously that would create some coiling as well. The bowl works best with a certain amount of water so probably won't match.

This gives me another idea that might work for my rez as well as DWC buckets. It could be a lot more quiet compared to bubbles, wouldn't require a powerful air pump but a simple water pump. To take a DWC bucket as an example, see attached image. Basically create a waterfall inside the rez, along the entire wall by overflowing a small gutter. Could that work better than air pump +bubble stones? In a DWC setup it would require a pump per bucket or a separate rez for the pump and then interconnect all buckets to keep the water level... but for the rez in my setup it would be easy to setup. Just a small water pump to fill a gutter along the inner walls of the box. Stretching the gutter down as in the left image (the purple thingy) would reduce splatter, using just the gutter part at the top would create more coiling. Instead of overflowing the gutter it could be a helix, like round stairs along the inner side of the bucket wall.

Or/and... add a sprayer or two more to my system but place them back in the rez... sounds simple and effective. 

I got a few other items I need to buy before my first hydroponic setup is complete, but I'm definitely getting the DO meter in a few months. The effect of combining methods (or extending the waterfall) won't add up endlessly but it still seems like a fun challenge to increase it with a few points compared to using bubbles.


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## legallyflying (Feb 4, 2013)

You might want to try and rent a DO meter. A good one is around $500.. 

Falling water is a great way to aerate things. I believe that agitator is the correct adjective in this case? Many sewage treatment facilities use agitation to entrain oxygen. That little floating donut in the middles of the sludge pond making all those frapachino bubbles...that's an agitator mixing in O2. 

Any simple waterfall or jet blasting into the standing water will provide plenty of oxygen to a reservoir. 

The blue stones work fine although the down side is that they are fragile as fuck, and worse after a run or two. You can't get the hoses off without breaking them. Trying all the different stones etc ...and this is for DWC plant containers, not reservoirs, the round grey stones seem to provide the bet bang or the buck. 

They put off a lot of air. The bigger, more expensive 4" ones don't do any better than the smaller ones, they are durable as hell and you can get them for about $2 a piece. 

I have about 32 of them now. About the 4th week of flower, before they get completely burried in the root ball I swap them out for clean ones as they do tend to get slowly clogged if your using beni tea. 

For the dirty ones...
1. I rinse them off then let them dry
2. Then I boil then for about 2 minutes
3. Let dry again
4. One last boil for about 2 minutes. 

The drying/boiling really seems to clean them out well and they are ready to go. 

I should have tested air pumps. I used to think that air pumps had to be hot and loud...ala the ecoplus commercial. Well I bought a 150 liter? Alita style air pump from eBay "pond master". Holly fucking shit these things are awesome! Sooo much air, higher PSI, quieter than my oscillating fans, and they only get to about 95 degrees. The Eco plus got up to 138 degrees! 

Cheers


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## Sativied (Feb 4, 2013)

I don't know if agitation refers to adding oxygen specifically or if it is merely a side effect of agitating (mixing fluids, like a washing machine agitator), but I considered using a wavemaker (for aquariums) to increase the motion. I would be placing another warming element in the rez so figured I'd better spend the money wiser but for example: http://www.amazon.com/1300-Coral-Aquarium-Makers-Powerhead/dp/B002480V32/ 

Makes me wonder if creating a whirlpool in a DWC bucket by a rotating fin at the bottom would work - would obviously need good protection against roots but could be very quiet. Might even do good pressing the nutes against the roots continuously. 



legallyflying said:


> I should have tested air pumps.


Or the same pump on different volume of water and try and work out a rez to air pump capacity ratio. How much would it for example have mattered if you had the same bubble stone in half (or double) the amount of water. Continuing to reduce the amount of water to a minimum should also give an indication of what the max feasible DO would be using an average air pump + bubble stone method. Seems a little pricy to actually test a bunch of different pumps but it sure would be interesting.

Renting a DO meter, that's a good suggestion. Not sure if I can find something in my area that rents to consumers, but a quick search shows there might be options. I noticed the $140 Milwaukee DO meter, would it not be good enough for a test? I guess the cost of the others listed sort of answers that question already.

Getting my rez in tomorrow, then I'll know the height of the return waterfall 'inside the rez' as well. I think I'm going for something like a gutter on the inside of the rez in which the return water drops, and maybe use a small 12v pump I already have to keep it going non-stop.


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## legallyflying (Feb 4, 2013)

I think your thinking about it too much. You know how I aerate my 70 gallon rez? 

I have a $10 water pump that shoots water straight up through a 3/4" hose and then it splashes down into the water. done and done.


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## hotrodharley (Feb 4, 2013)

legallyflying said:


> I think your thinking about it too much. You know how I aerate my 70 gallon rez?
> 
> I have a $10 water pump that shoots water straight up through a 3/4" hose and then it splashes down into the water. done and done.


That's how I did my crawdad farm. Swamp cooler pump - water up 9 feet and shot out to fall back down aerated. Cheap and suggested by Louisiana State University.


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## nick88 (Feb 4, 2013)

legallyflying said:


> I think your thinking about it too much. You know how I aerate my 70 gallon rez?
> 
> I have a $10 water pump that shoots water straight up through a 3/4" hose and then it splashes down into the water. done and done.


 Yep, no sense in trying to reinvent the wheel so to speak. Sometimes people tend to over complicate a fairly simple process as growing MJ.


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## JordanTheGreat (Feb 4, 2013)

Not to beat this horse anymore... but, i read a test done by max yield magazine cOncerning DO.According to them the saturation point of oxygenation is something like 6ppm. They were able to achieve supersaturation by adding a venturi to the existing aeration methods @ a final reading of 8ppm. I used a venturi on the return pump of my UC hybrid project and i can see bubbles forming on tons of submerged surfaces... its actually kind of cool


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## ArCaned (Feb 5, 2013)

Excellent comparison write up 10/10


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## Sativied (Feb 5, 2013)

nick88 said:


> Yep, no sense in trying to reinvent the wheel so to speak.


That expression should have been deleted from history after tank treads were developed. No seriously, you guys are probably right.

It just seemed attractive to combine two or more easy/simple methods, if it were to increase the values noticeably. But besides I won't be able to notice a small difference without a meter, it seems the max saturation point using easy/simple methods is reached even sooner than I at first expected - I'd probably just end up making a bigger mess with more noise.

I'll just keep it simple then, thanks for indulging nevertheless!



JordanTheGreat said:


> I used a venturi on the return pump of my UC hybrid project and i can see bubbles forming on tons of submerged surfaces... its actually kind of cool


That does sound kinda a cool as well as a reassuring sign.


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## turkeybaser (Feb 26, 2013)

Sorry to bump an old thread, but I have searched the airstone debate, and I have yet to find any info about hose diameter. This gets more into fluid dynamics and pressure but why is there no talk of air hose diameter? These airstones have 1/8 in intakes. I choose the micro diffusers because most of them come with a 3/8 inch intake option, meaning I can push air at a wider diameter, hopefully pushing more O2. Sure the tube goes down to 1/8 at the diffuser, but isn't it better to push a larger volume of air to the diffuser? I've searched, but there isn't much on this. Maybe I've missed something.


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## legallyflying (Feb 26, 2013)

Turkey, it gets really complicated fast but you can calculate it. The big thing is how well your pump fights against back pressure. Small hose isn't that bad, but long lengths of small hose are. When I had a 12' long grow room with double rows, I ran 3/4" line to a t and then ran 3/4" to each of the two manifolds. 

Now that my room is 25 x 15 I run a single 3/4 inch irrigation hose around the room. Then I just tap into it with the individual air stone lines. Nice even pressure that way and short lengths of small hose. 

If you are running less than say 5' I wouldn't sweat it.


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## Malevolence (Feb 26, 2013)

I wonder if different airstones would have more of a noticeable change in effectiveness if you weren't blowing up your buckets with 110 L/min. At that rate, could prob just stick the hose in the bucket and reach saturation.

I only read the OP, sorry if this has already been addressed.


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## legallyflying (Feb 27, 2013)

Perhaps. But the largest take away, for me anyways, is that total saturation is pretty easy to achieve. So spending your money on diffusers or micro pore stones is probably just a waste of money. Same with vortex and ways to achieve higher than normal saturation. There is a pint where there is TOO MUCH OXYGEN!! It will start messing with your roots. I was running a UC and having problems. I called UC and he said "shit, your putting like 4 times the recommended amount of air in the system. I scaled down and the problems went away. 

Take home point... I'm fucking killing it with 2" round stones and a good pump. You should be able to as well


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## inspired333 (Mar 20, 2013)

Hey Legally,
Good thread, read the whole thing - even the wars. 
Do you have any grow threads, I'd like to see what you're working with. How many buckets/sites are you running off that "pondmaster ap-100" (right? 148L/min)? 
At first I was thinking 10L/min per 5 gal bucket (not 5 full gals water in each when in system mind you) for pump sizing, though I planned on an ~80L/min pump for 4 sites (plus control/res) at around 20L/min so I could upgrade and use it for 8-ish buckets later on. Now I'm thinking 80L/min+ regardless and see how it works on buckets. Planning on the simple blue-ish cylinder ecoplus(i think) 2 inch air stones; either 1 or 2 of'em tee'd of per bucket.

Note: I have an alita al15 (20L/min) and I have to micro pore (small or medium size single) stones tee'd off and when I throw that in a single full 5 gall is pretty awesome. I want at least near that in each grow site :/ I guess 10 to 20 lpm/site.

Thanks for ANYONE that wants to still discuss this, haha.

Peace


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## inspired333 (Mar 21, 2013)

legallyflying said:


> ...There is a pint where there is TOO MUCH OXYGEN!! It will start messing with your roots. I was running a UC and having problems. I called UC and he said "shit, your putting like 4 times the recommended amount of air in the system. I scaled down and the problems went away.


Hey Legally, 
I wanted to know about your Pondmaster AP-100 air pump setup. How is it working? How many lines from manifold are you running, and how many air stones? How long have you had it now? Does it stay a lot cooler than that Ecoplus commercial air one does?
Well my question is posted in your thread.
I tried to PM ya as well, but your inbox is full or something.
-->The quote above really emphasized in my mind that I wanted to pick your brain about that Pondmaster/Supreme air pump you're using. You have the AP-100 right? 148 L/min (!!) I'm thinking the 90 L/min AP-60 for 4-5 buckets (and up to 8-9 total). What do you think. And tell me about your pump setup please? 

Thanks for your time,

Ins.


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## legallyflying (Mar 22, 2013)

The AR 100 fucking rocks dude. Like seriously. I honestly don't know why hydro stores sell the piece of shit Eco pumps. They get so fucking hot and Jesus are they loud. The pondmaster is warm but in no way hot. 

Depends on price between the two pumps. I would probably go with the 100 and run two stones for each bucket. The stones can clog. Some do some dont and I can't figure out why. So it's always nice to have a back up. 

I am running 12 stones of that pump. I don't use a manifold as the buckets are spaced about 3 feet apart and that would mean tons of black tubing everywhere. What I did was hook the pump up to a loop of 1/2" funny pipe...the stuff for drip irrigation systems. It's run behind all the buckets then I just tap into it right behind each bucket with the drip irrigation barbs. 

FYI. I just ordered a dozen of the sintered alita airstone. They make a 2" oval stone now and the sintered material is supposed to never clog. They R about $7 each. I'll keep you posted and glad you liked the thread.


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## Cannabisseur (Aug 11, 2013)

This is an excellent thread, but I'm curious if anyone knows how quickly roots absorb oxygen. I'm sure it varies from plant to plant, but does anyone have any idea? I would think this would be a very important variable to this test.


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## Alaric (Aug 11, 2013)

Heisenberg said:


> The real reason to pay attention to DO levels is to prevent pathogens from growing. Pathogens have a hard time living in any solution aerated to 6pp-8pp DO.
> 
> *Interesting-----how did you conclude that?
> *
> ...


Stay safe and have fun,

A~~~


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## legallyflying (Aug 13, 2013)

LOL, diggin uo the past with this thread. Yes, the pondmaster pumps rock for sure. I just started a big..ok, HUGE room but decided to screw all the hydro worries and just run hempy buckets. 

no, there won't be a grow thread. Not worth the time and energy and, well, risk


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## Sativied (Aug 15, 2013)

legallyflying said:


> I just started a big..ok, HUGE room but decided to screw all the hydro worries and just run hempy buckets.
> 
> *no, there won't be a grow thread. * Not worth the time and energy and, well, risk


That's a shame. I understand, but I'd be interested in hearing more about your motivation for going hempy buckets, what exactly 'all the hydro worries' is that you want to avoid, and especially how you think about the switch to hempy buckets at the end of the cycle. Doesn't have to be a grow thread, can be one post


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## legallyflying (Aug 17, 2013)

That's an easy one

Root rot
Chillers 
Running air pumps
Scrubbing and bleaching air stones
Scrubbing the Rez 

Vs 

Mix perlite and a little coco 
Go to the dump at the end of the cycle


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## Sativied (Aug 17, 2013)

Ok, I can imagine in a "HUGE" room, running "chillers" is a major downside. Running air pumps, valid downside even though it doesn't seem like a major one by itself. But once you do, do you still get root rot, still need to scrub the rez? Have you considered other options than hempy? Just curious, I'm going to build a new closet for next round and want to keep an open mind till I buy PVC again.

I guess I should read through that Hempy thread some day... someone recommended it in my first thread at RIU, it just seems a little boring, sort of like growing on soil. And the continues monitoring of PH and ppm gives me so much feedback, I wouldn't want to miss that again. 

I never scrub my rez or airstones. I run an airpump + stones just to optimize DO (have plenty of circulation and 3 waterfalls already), and my rez smells fresh all the time. Only thing I do is throw 2 caps of bleach in it about an hour 'before' I refresh the rez. It's probably a bit like with bud rot, I haven't had root or bud rot yet so I'm not too worried about it either. Surely that'll change once I encountered it but so far so good.



legallyflying said:


> Go to the dump at the end of the cycle


Have you considered Mapito? Not saying it's better or whatever, but I find it interesting that I don't see it here at RIU, while it's so popular amongst commercial (1gpw+) growers in NL. Just slabs of mapito with rockwool cubes on top of it, some cut a small square in the slab to insert the cube. You won't have to dump the medium for several cycles.


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## legallyflying (Aug 17, 2013)

I use shit tons of air and if I don't run Benies I get slime. Like instantly. Even with zone or h2o2. Bleach is an option but I just said fuck all that noise...

I just went back to ebb and flow. Just easier 

On the big room though. We are rocking trees.. They are 6' tall and we haven't put then in the room yet! Mostly because the room is just getting finished. Anyways, trees need 18 gallons of perlite each. 

I'm completely exhausted dude. I hung 4 12" max can fans from the ceiling, painted the whole room, installed the main controller board and hung 18 ballasts on the wall. Which was fun compared to yesterday...running 180 feet of 4/0 aluminum wire from the main panel to the new meter. Uggggggh


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## Sativied (Aug 18, 2013)

legallyflying said:


> They are 6' tall [...] need *18 gallons of perlite each*. [...] hung 4 12" max can fans from the ceiling,[...] hung 18 ballasts [...]running 180 feet of 4/0 aluminum wire


Yeah, that does sound "HUGE".  It's shame you won't be doing a grow thread, understandable though.


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## legallyflying (Aug 18, 2013)

I might snap a couple pictures of the set up once it's all in but my good wide angle camera lens is at the repair shop 

Plus. While it is nice to get the "sweet dude" when starting a nuce grow log..grow threads are allot of work and unfortunately, you (I) never learn anything new, you just end up asking questions for the newbs. 

Over it. I'll send you some pictures though


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