# High Pressure Aeroponics - Pump Design/mister layout/misters...



## muleface (Oct 21, 2016)

I haven't really found a lot of information on this subject. The basic premise I have gotten is as follows...

- 80-100 PSI pump
- around a 40 micron droplet from some kind of misters
- run pump from 5 seconds to 2 minutes every 4 to 15 minutes
- Pre-Pressurize Accumulator Tank
- Electrical-Solenoid hooked to an adjustable relay timer

Subjects I would like to discuss:

- what misters work best?
- size orifice on mister
- material they are made from

How many misters per Square foot, or would this be per cubic foot, or perhaps both need to be considered?

How do you size the accumulator tank? I would assume you would figure out the misters output and size accordingly, but how. 10 misters, 1/2 an hour output per mister. 5 gallons per hour total , so 10.6 ounces per minute, this would be based on PSI of the pump too.

how is the pipe laid out?

best nutrients to reduce clogging

creating redundancy for the inevitable pump failure. 

actual data from grows and how they size up against other methods

This seems like a good overview site, but I would like to hear from actual pro growers that use this method.
http://aeroponicsdiy.com/


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## muleface (Oct 21, 2016)

My current system is as follow.

4 - 55 gallon tubs (20 in wide, 44 in long, 18 in deep)
45 psi pump
48 - .012" orifice (0.3 mm) brass and stainless misters (12 per tub)
all being run with 1/2 inch pvc piping.
a timer that runs it 15 seconds every 4 minutes


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## muleface (Oct 22, 2016)

WOW. ok....that is impressive. do you still run that kind of setup? That seems like a lot of moving parts, but that is the exact kind of answer I was looking for. At the end of the day, did you notice a real difference at harvest say compared to other setups you ran? Or did you seem more of an incremental increase? say, a couple of extra grams per plant... 

How long was your cycle? Say 1 second of misting, and 5 minutes of down time? 

I would love to see some pictures of you have any of that setup.


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## CannabisNerd (Oct 22, 2016)

nxsov180db said:


> With true HP aero you want a very low misting time, around a couple seconds down to even tenths of a second. I used to use Teffen nozzles, a pretty small accumulator tank, an aquatec 8800, a solenoid for every mister, You want to lowest amount of volume between the solenoid and the mister nozzles (ex. you would not want to run a 2 foot length of 1/2 pvc between the mister and solenoid. I used to thread the nozzles directly into the solenoids, you want and instant on and off). Nutrients, as long as you stay away from organic you are good to go, I used GH micro/grow/bloom, use an inline 200 mesh filter on the intake side of the pump, I never had a clog. Misters per cubic measurement really depend on the nozzles, pressure, ect.. Only way I see you getting that part down is to hook nozzles up and trail and error, getting your feet wet with HP aero is just that, a whole lot of trial and error. I have A LOT of parts (pumps, nozzles, solenoids) that I would sell to you if you wanted...


Excellent explanation. Was easy to follow and makes perfect sense. I took a screen shot of this so I can have the info on hand when I do my build. Aren't tefen nozzles plastic? You didn't find that the brass worked better? Thanks for the info


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## muleface (Oct 23, 2016)

nxsov180db said:


> https://www.rollitup.org/t/new-aero-setup-first-day-of-flower-comments-or-suggestions.708587/#post-9495132
> 
> You'll see pics here on the first post I beleive.


in the pictures you linked us to, what did you use as a base for your system. I am using storage containers, but im not really loving them. did you make your base?


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## CannabisNerd (Oct 24, 2016)

nxsov180db said:


> Yes tefen are plastic, I actually did use nickle plated brass ones at first in a different HP system that ended up not being very well designed, not because of the nozzles but just the design overall wasn't very good. But the tefen nozzles are pretty good I think, they have a little screen built into them as a last resort filter and I've never had one clog, they are also pretty affordable.. They throw a good consistent mist too. I bought a couple different styles to see which one gave the best mist and went from there..


OK great. Even better they have a filter in them, I ran a couple a long time ago and couldn't remember, I think I ran brass but I know I did use the plastic ones too. The filter seems much more logical to use. Thanks again


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## CannabisNerd (Oct 24, 2016)

muleface said:


> in the pictures you linked us to, what did you use as a base for your system. I am using storage containers, but im not really loving them. did you make your base?


Have you considered 6" round pvc for your channels? The way I had my system set up was with 6" pvc with 3" net pots that held the plants. I ran the "fork" manifold along the pvc and it was along the top side of the pvc, misters screwed into the top part of the pvc between plants so roots couldn't grow into them. Is the base that your talking about the container the plants sit in?


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## muleface (Oct 24, 2016)

Yeah. I'm asking about the root chamber. My current setup allows about 15 inches of roots to hang.


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## muleface (Oct 31, 2016)

nxsov180db said:


> With true HP aero you want a very low misting time, around a couple seconds down to even tenths of a second. I used to use Teffen nozzles, a pretty small accumulator tank, an aquatec 8800, a solenoid for every mister, You want to lowest amount of volume between the solenoid and the mister nozzles (ex. you would not want to run a 2 foot length of 1/2 pvc between the mister and solenoid. I used to thread the nozzles directly into the solenoids, you want and instant on and off). Nutrients, as long as you stay away from organic you are good to go, I used GH micro/grow/bloom, use an inline 200 mesh filter on the intake side of the pump, I never had a clog. Misters per cubic measurement really depend on the nozzles, pressure, ect.. Only way I see you getting that part down is to hook nozzles up and trail and error, getting your feet wet with HP aero is just that, a whole lot of trial and error. I have A LOT of parts (pumps, nozzles, solenoids) that I would sell to you if you wanted...


so how did you power your solenoids? you had a bunch of them, were they 12v? did you use an ac/dc adapter? how did you wire them?


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## Zekie (Nov 3, 2016)

Your pump pressure seems a bit low, by the time all the misters are running it's going to drop significantly. 

Additionally you will be fine with 4" or 6" fence posts, I've made about 10 systems using them and they work wonderfully (many thanks to stinkbud). Round PVC is harder to work with regarding getting a good seal with your net pots, the last thing you want is leaking.

These are some good misters that have screens to filter out particulates & prevent clogging: https://hydro-gardens.com/product/monarch-misting-nozzles-m-5-6w405/

Not sure why you would want a solenoid on every mister, unless you want to throw a bunch of money down the tubes and waste a bunch of time coding them. You can get a 12V 160PSI diaphragm pump off of eBay for about $15 which will run a bunch of misters however, if you are fogging up the nutrients, the fog will allow you to run less misters because it will fill your whole root zone easily plus you will have plenty of room for expansion to other systems using the same pump.

Best of luck to you!

Peace,
Z


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## Zekie (Nov 3, 2016)

nxsov180db said:


> you should have almost no run off, any mister inside of PVC fencepost or anything that small in size is going to form water droplets on the inside surface because the mister doesn't have enough room in front of it to disperse...


Not sure where you got your definition of aeroponics from but no one uses your definition, read R.J. Stoner's, NASA's or any academic research on the subject. The 'forming of water droplets on and inside surface' is an impossible standard that isn't used anywhere. The definition of aerponics doesn't change from low pressure to high pressure.

Peace,
Z


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## Zekie (Nov 3, 2016)

nxsov180db said:


> Low Pressure Aero and High Pressure Aero are indeed 2 different things, while the actual definition of Aeroponics itself may remain the same, the definition of low and high are different.. Inside of a 6" tube you are going to be forming a lot of water droplets, while it is true that avoiding the formation of water droplets entirely may not be possible that does not change what your are trying to accomplish with HP Aero. Inside of a 6" tube 1/4 to 1/2 of your nutrient solution is going to be water droplets formed on the inside wall of the PVC and most of that will end up down the drain/wasted, kind of goes against the objective which is using the smallest amount of nutrients/water as possible. The point I guess I am trying to get across here is that if you are going to use 6" tube then you may as well just use low pressure aero since there would be no advantage to high pressure aero...


Here's a good high pressure system and I have zero affiliation with them whatsoever: 




They cycle the timer 2 min off 30 seconds on, most people use 4 minutes on and 1 minute off (see the Stinkbud thread) which is the whole genesis for the Titan Apollo 3 ( http://www.titancontrols.net/products/timing/apollo-3.aspx ). Additionally, look at the plethora of high pressure commercial aeroponics videos on Youtube, they all use a gutter system in some way. 



nxsov180db said:


> you may as well just use low pressure aero since there would be no advantage to high pressure aero...


The advantage of high pressure aeroponics over low pressure aeroponics it the super oxygenation of the nutrient mist when atomized. It has nothing to do with drying out the roots between pump cycles or the roots touching standing water (which they are going to anyway unless you have a 20 foot column beneath your roots).

Peace,
Z


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## muleface (Nov 3, 2016)

nxsov180db said:


> Low Pressure Aero and High Pressure Aero are indeed 2 different things, while the actual definition of Aeroponics itself may remain the same, the definition of low and high are different.. Inside of a 6" tube you are going to be forming a lot of water droplets, while it is true that avoiding the formation of water droplets entirely may not be possible that does not change what your are trying to accomplish with HP Aero. Inside of a 6" tube 1/4 to 1/2 of your nutrient solution is going to be water droplets formed on the inside wall of the PVC and most of that will end up down the drain/wasted, kind of goes against the objective which is using the smallest amount of nutrients/water as possible. The point I guess I am trying to get across here is that if you are going to use 6" tube then you may as well just use low pressure aero since there would be no advantage to high pressure aero...


I'm going to have to agree, HP and LP are totally different animals. My purpose to starting this thread was to design the more insane version. While I can't say whether or not one works better then the other, I have no idea. I can say that the idea of HP is to use a extremely short burst of water, with a very fine mist.

http://www.agrihouse.com/secure/shop/item.aspx?itemid=24

*Soil-less growing from start to finish includes:* High pressure pump unit w/ high capacity accumulator, digital timer (multi-settings/ programmable), 26 ea. spray jets (.025" orifice), power strip w/ GFP, aeroponic chamber (48 in. Long x 18 in. wide x 16 inches deep) w/ 160 plants support structures, stand, 340 watt light array / nutrient recycling reservoir (7-gal) w/ auto-refill, 3-stage effluent filtration, stainless steel delivery hoses, pre-filter w/ reverse osmosis pure water supply system, drain connectors , plant growth suspension bar, reservoir over-flow protection, auto-refill, oil-filled pressure gauges, by-pass valve, additional chambers expansion ports, 85 page installation manual and growers guide, and cleaning tools.

While the above is fn crazycorn, I think that something could be made for about $14000 less and do just about the same thing. 

I have issues with my system taking about 8 seconds to get to full power, then it has to drop back down. I get large droplets. It should be 50 micron drops for about 1 second. Then wait until just before the roots are dry to mist again.


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## Eskander (Nov 3, 2016)

I'm looking at building a seat up of my own but I'm growing chilli peppers with a longer life cycle than most people here would want. I've been doing a lot of reading on HPA and there is a ton of misinformation out there. What is worse is that there is stunningly little real literature. What I did find on positioning is a bit contradictory at first but I'm happy to share my conclusions for what they are worth.

First things first, you need a lot of vertical space for roots. For peppers, I need about two feet. For potatoes you need about three. For MJ, you can probably get away with less but you really are better off with breathing room and the reason comes down to the nebulizers positioning. You want a mister pointed up halfway up the root chamber. A mister every square meter is actually enough even for large plants.


These are in a 1 meter tall chamber and the tops are around 8 feet tall.

Having a ton of misting heads spraying on the roots directly is exactly the wrong thing to do as it encourages lateral root growth that ultimately shields the interior of the root bundle. People talk about the <50 micron mist behaving like air which will get literally everywhere but that kind on aerosols behavior starts at about 1 micron. Big bushy roots are sexy for pictures but aren't really ideal when it comes to hydration and nutrient uptake. Think of it this way, the outside of a bush has all the leaves cause the inside gets no light. Same deal. You want roots with high overall surface area without being bushy enough to shield the core from the mist.

-Eskander


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## muleface (Nov 3, 2016)

Eskander said:


> I'm looking at building a seat up of my own but I'm growing chilli peppers with a longer life cycle than most people here would want. I've been doing a lot of reading on HPA and there is a ton of misinformation out there. What is worse is that there is stunningly little real literature. What I did find on positioning is a bit contradictory at first but I'm happy to share my conclusions for what they are worth.
> 
> First things first, you need a lot of vertical space for roots. For peppers, I need about two feet. For potatoes you need about three. For MJ, you can probably get away with less but you really are better off with breathing room and the reason comes down to the nebulizers positioning. You want a mister pointed up halfway up the root chamber. A mister every square meter is actually enough even for large plants.
> 
> ...


That is fucking awesome. Is that red potatoes?

wait are you staying the root chamber is like 3 feet and then there is 8 feet of green coming out of it. so like 11 feet total? how do you hang lights for that?


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## Eskander (Nov 3, 2016)

muleface said:


> nutrient recycling reservoir (7-gal) w/ auto-refill, 3-stage effluent filtration...


As far as nutrients go, you pretty much need to commit to drain to waste. Nutrient uptake is around 1/3 in a single pass. There is hardly any reason to recycle what is left and there are a lot of reasons not to. You never have to screw with pH or nutrient tank top off and rebalancing but you also have far lower risk of spreading pathogens between plants. With hardcore filtration you can pull out the fungal stuff easily, the bacterial stuff with a lot more effort but you have zero chance of filtering out viruses. Beyond the obvious advantages there, you have things that are never really discussed on non-technical forums like this. People that have read up enough are probably aware of waste excretion by the roots. What this really amounts to gets pretty much zero attention. 

Beyond analogies about drinking your own piss, let me get into some specifics. Plants excrete a pile of signaling compounds through the roots. Some of these are signaling to other parts of itself like, "I'm growing here, grow some other direction." Other things are directed at other plants and are more to the effect of, "Grow my way and I'll scoop your eyes out with a melon baller and piss in the sockets." In either case, you really don't want to constantly expose a plant to those excretions even in trivial doses.

The upside is that your nutrient consumption rate is low and you are using low concentrations anyway. Once you have spray times dialed in, your loss down the drain isn't all that high anyway. Dialing the spray time in isn't trying to achieve what most people think. There is no reason to ever let the roots dry. They don't need all that much oxygen and they don't absorb it from dry air well anyway. All the mysticism about getting as much oxygen to the roots as possible is baseless. Plants aren't designed to need tons on oxygen to the roots and many can deal with submerged roots with zero aeration as long as the temperatures are low. There is actually enough oxygen in the photosynthate flowing to the roots to cover some plants. That is how things like rice deal with the low DO in the warm stagnate water they are submerged in.

As far as tuning in the on time, keep the roots moist and try to have as little excess that ends up going right down the drain without time on the roots.

-Eskander


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## Eskander (Nov 3, 2016)

muleface said:


> That is fucking awesome. Is that red potatoes?
> 
> wait are you staying the root chamber is like 3 feet and then there is 8 feet of green coming out of it. so like 11 feet total? how do you hang lights for that?


Yes, I mean 11 feet total.

 

They used a fusion based lighting system...

-Eskander


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## Eskander (Nov 3, 2016)

It occurred to me that many people here may not have a basis for comparison so here is what a mature plant usually looks like:

 

Just in case you can't count to potato 

-Eskander


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## muleface (Nov 3, 2016)

Eskander said:


> As far as nutrients go, you pretty much need to commit to drain to waste. Nutrient uptake is around 1/3 in a single pass. There is hardly any reason to recycle what is left and there are a lot of reasons not to. You never have to screw with pH or nutrient tank top off and rebalancing but you also have far lower risk of spreading pathogens between plants. With hardcore filtration you can pull out the fungal stuff easily, the bacterial stuff with a lot more effort but you have zero chance of filtering out viruses. Beyond the obvious advantages there, you have things that are never really discussed on non-technical forums like this. People that have read up enough are probably aware of waste excretion by the roots. What this really amounts to gets pretty much zero attention.
> 
> Beyond analogies about drinking your own piss, let me get into some specifics. Plants excrete a pile of signaling compounds through the roots. Some of these are signaling to other parts of itself like, "I'm growing here, grow some other direction." Other things are directed at other plants and are more to the effect of, "Grow my way and I'll scoop your eyes out with a melon baller and piss in the sockets." In either case, you really don't want to constantly expose a plant to those excretions even in trivial doses.
> 
> ...


This is an interesting idea. From a nutrient perspective its not really wasteful. I run about 7 seconds every 5 minutes. I have 48 nozzles that run at 1/2 gallon each an hour. So if i was running full time that's 24 gallons a day or 1 gallon an hour. But i'm really only running at 84 seconds of run time an hour, so that's about 34 minutes a day, that would bring my total water usage to 73 oz a day. That's only 4 gallons a week. Hell, I lose that to evaporation anyway. Also, if i need to add more liquid in my reservoir, i can just mix up another gallon at a my normal concentration, because the reservoir should be always at the right concentration. Plus, at the end of the week I throw out my nutrients anyway, i usually make a 5 gallon bucket of it and add water as needed. So really, there is no loss at all. I could toss the large trash can i am using, and use something like a 5 gallon water container with a small opening to avoid evaporation. I don't have to f with PH, The system would be a hell of a lot cleaner, I love it!

This is a great idea...Welcome to RIU. 

Just a word of advice, i don't think that guy in the picture likes his picture taken. he looks like he's going to attack!  

Please keep the good idea coming!!

MF


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## Eskander (Nov 3, 2016)

muleface said:


> Just a word of advice, i don't think that guy in the picture likes his picture taken. he looks like he's going to attack!


Oh, Oddjob? Yeah... we got him some meds to deal with his hat fetish and he is mostly harmless now 

-Eskander


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## muleface (Nov 3, 2016)

Eskander said:


> Yes, I mean 11 feet total.
> 
> View attachment 3822241
> 
> ...


that is crazy, what is the production output doing aeroponics compared to just putting them in the ground?


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## Eskander (Nov 3, 2016)

muleface said:


> that is crazy, what is the production output doing aeroponics compared to just putting them in the ground?


It is specialized application. The point is to generate lots of small potatoes for use as seed stock. In that context it is great cause not only do you get monster plants that can put a ton of energy into making potatoes but you can harvest repeatedly unlike on plants in soil.

Here is a write up on the system.

-Eskander


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## muleface (Nov 3, 2016)

That PDF is great. Its well worth reading. Also, glad you are out there helping the worlds hungry!

also, can you explain what they are saying here.

"Farran and Mingo-Castell (2006) used timers calibrated so that the system can work for 10 seconds every 20 minutes. During cool nights its only necessary to activate the system for 15 minutes every hour. During day we need 15 min. after every 15 min. of inactive period."

So what the cycle they used there? 10 seconds every 20 minutes? or something else?


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## Eskander (Nov 3, 2016)

Nope, when I read that I was like WTF? The lower on time at night makes sense but the "10 seconds every 20 minutes" thing doesn't. I think in the end, you just need to optimize spray duration and off time vs transpiration needs and RH in the root chamber. Keep them moist with as little run off as manageable.

-Eskander


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## Atomizer (Nov 4, 2016)

muleface said:


> I'm going to have to agree, HP and LP are totally different animals. My purpose to starting this thread was to design the more insane version. While I can't say whether or not one works better then the other, I have no idea. I can say that the idea of HP is to use a extremely short burst of water, with a very fine mist.


The idea of HP is to provide a mist environment where the roots can feed and breathe at the same time, all the time  Ideally you need to maintain a constant level of mist in the chamber comprised of droplets in the correct range, namely 5-80 microns with the bulk being 30-50 microns. If the roots are coated by a film of water, they may as well be in dwc. Dissolved oxygen plays a minor role in a truely aeroponic environment considering how little water is needed to fill a large root chamber with mist, typically less than 10ml (2tsp) per 1000L (264gal).
Root chamber RH% is not very useful for controlling the mist, water vapour is a gas which roots dont use. If you monitor the RH% in the chamber you`ll find it takes a long time to peak after the misting pulse and even longer to fall.If that wasnt bad enough,it never drops back to where it began either  In a nutshell, dont use chamber RH% to govern the mist timing if you wont keep the plants alive


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## Eskander (Nov 4, 2016)

nxsov180db said:


> @Zekie Water can only hold a certain amount of Dissolved Oxygen, with the combination of an airstone and water being sprayed inside the root chamber (whether it be from LPA or HPA) you're going to be at the upper limit of Dissolved Oxygen in either system.
> So people on Stinkbud's thread are running HPA with 4 minute on/1 minute off mist times?


DO is relative to water temperature. Colder water holds more dissolved gas until just shy of freezing. You are right in that the DO in the water is going to be at the cap with even a small amount of aeration but delivery to the roots isn't as uniform as you'd think. The roots have a few effective microclimates. With pretty much any hydro or aero set up, the roots on the outside are exposed to more DO than the roots near the middle.

As for high uptime on the sprayers, that pretty much eliminates being able to do drain to waste which is one advantage but it also causes problems.

"With a continuous fog, the plants become dependant upon the constant mist and interruption of the fog would soon cause loss of plant life. The continuous mist can also contribute to fungal and bacterial growth in the vicinity of or on the plants." [Coston et al., 1983]

"...interval/duration techniques produce healthier, more natural roots than constant fog or hydroponic techniques . The interval/duration spray method conditions the plants to thrive longer on lower moisture levels and also may reduce pathogen infection. Roots propagated with interval/duration aeroponics are much more resistance to interruption of the misting regimen." [Stoner et al., 1998]

-Eskander


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## Eskander (Nov 4, 2016)

Atomizer said:


> Root chamber RH% is not very useful for controlling the mist, water vapour is a gas which roots dont use. If you monitor the RH% in the chamber you`ll find it takes a long time to peak after the misting pulse and even longer to fall.If that wasnt bad enough,it never drops back to where it began either  In a nutshell, dont use chamber RH% to govern the mist timing if you wont keep the plants alive


I'm probably thinking about this in too ideal of a situation but It seems that if you can find the on time that holds RH around 99% than you would be maintaining equilibrium with uptake by the roots. That would be optimizing for lowest possible water use rather than idealized growth though...

-Eskander


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## Atomizer (Nov 4, 2016)

RH% is a red herring, if you do a simple test you`ll see why  If the chamber is at 70% RH prior to the mist pulse, it`ll take 5 minutes or more to reach a peak RH and another 10 minutes for it to drop back to a stable value which will creep ever higher with every misting pulse.
If you use a 15 minute pause duration based on the chamber RH,it will lead to the rapid demise of your plants. A growroom can be well above 70% RH, if you hang some plants up with bare roots, they`d soon be gonners  
Constant mist and continuous mist are different things. If you have enough control over the mist, you can maintain the correct ratio of liquid, coverage and droplet size range relative to the chamber volume. Your references highlight the limitations of hydraulic nozzles in aeroponics, the lack of control (quality, quantity and coverage) results in a less than ideal environment. Using the interval may appear to work better but, in reality, its the only option they have to create an environment thats closer to the ideal, but not ideal because the nozzles they used arent capable of providing it  
If they conducted the same tests with AA nozzles, they`d likely come to different conclusions.


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## Eskander (Nov 4, 2016)

Atomizer said:


> RH% is a red herring, if you do a simple test you`ll see why  If the chamber is at 70% RH prior to the mist pulse, it`ll take 5 minutes or more to reach a peak RH and another 10 minutes for it to drop back to a stable value which will creep ever higher with every misting pulse.


RH is a tool like any other. If you use it right it is useful, if you don't than it is at best merely useless. The root chamber should never get close to a RH of 70. You will start pushing the plant into senescence by letting them get that dry. For any system that is working reasonable well, the RH in the root chamber should stay in the upper 90s. This means that if it drops below that, you need to spray. Is using that as your primary control for spray timing optimal? Probably not in most situations. Is it a useful failsafe? Yes.



Atomizer said:


> Your references highlight the limitations of hydraulic nozzles in aeroponics, the lack of control (quality, quantity and coverage) results in a less than ideal environment. Using the interval may appear to work better but, in reality, its the only option they have to create an environment thats closer to the ideal, but not ideal because the nozzles they used arent capable of providing it


No, they don't say that at all. They highlight the effects of basic physics. If you continuously spray perfect 30 micron droplets all at a constant velocity you still create problems no matter how much you are spraying. Too much and you will form droplets all over the out roots which will shield the inner roots from the mist. Get them wet enough and they will all stick together and make that problem worse. To little and you get very little water to the inside of the root bundle. Since the roots on the outside are finer and have more efficient impingement of the mist, they would grab too much. The core wouldn't desiccate since you'd always be near the dew point, but those roots wouldn't contribute much to water or nutrient uptake either. It actually works to your advantage to have variance in droplet size if your goal is to spray enough to coat all the roots while maintaining an airspace between them. 



Atomizer said:


> If they conducted the same tests with AA nozzles, they`d likely come to different conclusions.


Most of the mist size and velocity studies seem to have been done with compressed air driven venturi sprayers as it was the only way they could tune both the average droplet size and velocity at the same time. The researchers then seemed to move towards simple hydraulically driven sprayers once they had settles on a size and velocity range they felt was optimal.

-Eskander


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## Atomizer (Nov 4, 2016)

You dont spray continuously, you maintain a constant level of mist, much like maintaining an ideal air moisture balance in soil  Given the right hardware you can add silly small amounts of water to the chamber in the form of mist, literally down to 10th`s of a ml.
You cant replicate the performance parameters of an AA nozzle with hydraulics, its simply not possible. For example, to get the same coverage you`d need to use a lot more hydraulics, which increases flowrate well beyond the AA. You could reduce the pulse duration by the same factor as the number of nozzles. Replicating the output of a one second pulse of an AA using 10 hydraulics of equivalent flowrate, you`d be looking at a 0.1 second misting duration  The 0.1 second pulse wouldn`t generate the same droplet size range even with a accumulator and solenoids on every nozzle.
Believe me, i`ve tested pretty much everything and anything you can imagine and then some.
This single nozzle AA setup delivers full 360 coverage with 5-80 micron mist. Liquid down to 0.1ml per pulse. There`s no way to replicate it with hydraulics but it would be good to see someone try


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## muleface (Nov 4, 2016)

muleface said:


> This is an interesting idea. From a nutrient perspective its not really wasteful. I run about 7 seconds every 5 minutes. I have 48 nozzles that run at 1/2 gallon each an hour. So if i was running full time that's 24 gallons a day or 1 gallon an hour. But i'm really only running at 84 seconds of run time an hour, so that's about 34 minutes a day, that would bring my total water usage to 73 oz a day. That's only 4 gallons a week. Hell, I lose that to evaporation anyway. Also, if i need to add more liquid in my reservoir, i can just mix up another gallon at a my normal concentration, because the reservoir should be always at the right concentration. Plus, at the end of the week I throw out my nutrients anyway, i usually make a 5 gallon bucket of it and add water as needed. So really, there is no loss at all. I could toss the large trash can i am using, and use something like a 5 gallon water container with a small opening to avoid evaporation. I don't have to f with PH, The system would be a hell of a lot cleaner, I love it!
> 
> This is a great idea...Welcome to RIU.
> 
> ...


so it turns out my calculations were a smidgen off. My nozzles are using about 1/4 gallon an hour. Perhaps i have too many misters. I have 12 - .012 misters per 2x4 root chamber, and 4 root chambers. . They are running at about 100 or so psi. For now i have to go back to a closed system.


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## Atomizer (Nov 5, 2016)

The important thing to consider about a film of water is it acts much like a non aerated mini reservoir.The O2 and/or nute content of the film will be depleted long before the water. 
Droplets are also self contained reservoirs but with much smaller volume. You could view the mist as billions of individual, bite-sized, floating lunch parcels surrounded by air. A piece of 325 mesh screen is useful for getting an idea of just how small 40-50 micron droplets are..


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## Eskander (Nov 5, 2016)

muleface said:


> so it turns out my calculations were a smidgen off. My nozzles are using about 1/4 gallon an hour. Perhaps i have too many misters. I have 12 - .012 misters per 2x4 root chamber, and 4 root chambers. . They are running at about 100 or so psi. For now i have to go back to a closed system.


 

You could shave that a bit by dropping to 80 PSI But that only drops you to 38.5 gallons per week from 42 gallons per week. How big is your reservoir and how often do you end up changing it?

-Eskander


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## muleface (Nov 5, 2016)

ROFL! holy crap, I guess I was WAY off! 

Any suggestions on nozzle size, I am using .012, but the really high end systems seem to be using .016 or .024


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## Eskander (Nov 5, 2016)

Well, 42 gallons per week assumes you have an on time of around a second every 4 minutes back tracking from your 1/4 gallon per hour remark AND assuming that the chart is correct lol

Have you measured your actual emission per hour from a single nozzle?

-Eskander


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## Atomizer (Nov 5, 2016)

Catch all the liquid from a single nozzle in a poly bag during a single misting pulse and weigh it on a gram scale. Dont forget to weigh the dry bag first so you can subtract it from the final weight. The bag method takes account of mist run on which can equate to more nutes than the actual mist being delivered.


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## muleface (Nov 9, 2016)

so my plants were not doing great with my on for 5 seconds off for 8 minutes cycle. I changed it to 10 seconds on and 5 minutes off. Things seem to be going much better. I know that isn't how this is suppose to be done. But im too invested now to have dead plants.  Any idea as to why things were going poorly?


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## muleface (Nov 10, 2016)

if anyone is interested, i'm ordering these....

https://naturalfog.en.alibaba.com/product/60469699723-803143403/High_Quality_303_Stainless_Steel_Antidrip_Fog_Nozzle.html?spm=a2700.7803228.1998738836.185.DEKmvS

They won't turn on until they hit around 40psi, so it should keep the droplets more uniform. The sheet says 1000psi, but they make the lower pressure ones too. Anyway, I have to order 100 of them, but if someone else wants some, i can get more on my order. it will save you the hassle of needing to get more then you need.


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## Eskander (Nov 10, 2016)

There are two versions of those. A low pressure gated at 65psi and a high pressure gated at 350 psi. In theory you can just change the springs out to adjust that but, It would be best to be sure you are ordering the right one. The ones that are linked are high pressure gated.

-Eskander


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## Atomizer (Nov 10, 2016)

The brass anti drips are typically 75psi open, 35psi close for the low pressure version and 145psi open, 70psi close for the high pressure version. When the nozzles clog (which they will) they can be recycled into useful brass grub screws using a 10/24 thread tap. The milled edge makes them easy to tighten without tools


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## Eskander (Nov 10, 2016)

Atomizer said:


> The brass anti drips are typically 75psi open, 35psi close for the low pressure version and 145psi open, 70psi close for the high pressure version.


https://www.amazon.com/DerBlue-pressure-Anti-Drip-clogging-Nozzles，ceramic/dp/B01HYA1SBI/ref=sr_1_3?ie=UTF8&qid=1478813647&sr=8-3&keywords=anti+drip+nozzle

The high pressure nozzles have much higher gate pressures than that. These are made for use at 1000psi and their minimum operation pressure is nearly 600. I'm sure there is variance between manufacturers but most of them report the activation pressure on the HP ones as several hundred psi. They are way outside of what we have reason to use.

-Eskander


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## muleface (Nov 10, 2016)

the ones i ordered open at around 35 psi, i wanted them to open closer to 75, but i will take what i can get. They were about a buck a pop, shipping included. They actually (in the picture) look really nice. i only need about 48 of them, but had to buy 100, so i guess i'll have a couple of spares. 

quick question, my plants are pretty short and bushy, not leggy at all. is that a good thing or is short and bushy a sign they are getting too much light or not enough?


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## Atomizer (Nov 12, 2016)

Eskander said:


> https://www.amazon.com/DerBlue-pressure-Anti-Drip-clogging-Nozzles，ceramic/dp/B01HYA1SBI/ref=sr_1_3?ie=UTF8&qid=1478813647&sr=8-3&keywords=anti+drip+nozzle
> 
> The high pressure nozzles have much higher gate pressures than that. These are made for use at 1000psi and their minimum operation pressure is nearly 600. I'm sure there is variance between manufacturers but most of them report the activation pressure on the HP ones as several hundred psi. They are way outside of what we have reason to use.
> 
> -Eskander


Here`s a test vid from 7 years ago to give an idea of what 150psi looks like on a 0.3mm brass nozzle. I cant remenber if it was a fogco or an amfog but they`re all very similar ime The thing to note is the non symetrical narrow pattern doesnt alter much over a pressure range of 100-800psi so you`ll need quite a few to get the coverage. You`ll find this type of nozzle very prone to partial clogging, they`re almost impossible to unclog and wont perform the same as when they were new even if you can manage it 
I recommend having a lot of spare nozzles on hand and checking the ones in the chamber at least daily to make sure they are ok.






The flow rates of the nozzles you posted higher up the thread seem very high. The one in the vid is 2.7LPH at 150psi. Here`s the full list so you can compare the difference


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## muleface (Nov 12, 2016)

Lol. well I only needed 48, but I bought 100, so I should be covered. at least for now


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## Atomizer (Nov 13, 2016)

With good filtering you should be ok for a while. I used them with dtw and nutes filtered to 1 micron and it didnt help much


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## muleface (Nov 17, 2016)

got my misters today, I don't think my pump is up to the task of using them. Some open, others don't. The ones that do open don't mist very much. I pulled the spring out of them and tried them running without the antidrip feature. Without the spring they are fantastic misters, MUCH better then the brass ones i picked up on amazon. They sent me 303 stainless, they are pretty and very well made. The 2 piece design will make cleaning them much easer. I highly recommend them. If there is some kind of fluid dynamics expert out there in RIU land, i would be interested in figuring out the formula for finding out the psi per mister port. If i was going to guess, my 48 mister heads with my 100 psi pump drops my psi per mister down below the threshold needed to properly run the misters. I wonder what psi I would need to run them correctly.


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## Atomizer (Nov 18, 2016)

Make yourself an adapter so you can plug a pressure guage anywhere in the system, JG fittings make this pretty easy. If you`re using 1/4" tubing it doesnt take much to have a significant impact on the pressure. Its best to test the pressure at the nozzle position thats furthest from the pump/accumulator.
Check your pump spec for flowrate at pressure and then compare it to the combined flowrate of your 48 nozzles at the opening pressure. Elbows, tee`s, tubing length/diameter etc will also have an effect. Ballpark for the pump will be at least 1gpm @ 100psi. If its an accumulator driven system then the pump spec isnt important, just the losses in the plumbing


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## muleface (Dec 18, 2016)

so after what could only be described as total and complete failure, I have shelved my aeroponics setup. I will try dutch buckets, i'm told that i would have to go out of my way to screw this up. I hope that is correct.

Anyway, if anyone want to buy any parts of my system, i will part it out. Really the only thing worth salvaging would be the misters and pumps.

Maybe someday i will try this again, also, i would have to agree, I should have DTW vs recycling water. once 1 plant gets root rot, it spreads like wildfire.


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## Cindy Wang (Jul 11, 2017)

nxsov180db said:


> With true HP aero you want a very low misting time, around a couple seconds down to even tenths of a second. I used to use Teffen nozzles, a pretty small accumulator tank, an aquatec 8800, a solenoid for every mister, You want to lowest amount of volume between the solenoid and the mister nozzles (ex. you would not want to run a 2 foot length of 1/2 pvc between the mister and solenoid. I used to thread the nozzles directly into the solenoids, you want and instant on and off). Nutrients, as long as you stay away from organic you are good to go, I used GH micro/grow/bloom, use an inline 200 mesh filter on the intake side of the pump, I never had a clog. Misters per cubic measurement really depend on the nozzles, pressure, ect.. Only way I see you getting that part down is to hook nozzles up and trail and error, getting your feet wet with HP aero is just that, a whole lot of trial and error. I have A LOT of parts (pumps, nozzles, solenoids) that I would sell to you if you wanted...


Was wondering if you still had parts you would be willing to sell? @muleface I'm interested in your parts as well!


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## muleface (Jul 17, 2017)

Cindy Wang said:


> Was wondering if you still had parts you would be willing to sell? @muleface I'm interested in your parts as well!


I do have parts. Lots of them. I have a couple of high pressure pumps and a ton of nozzles. The rest of my parts are things it would be cheaper to pick up locally then it would be to ship (pvc, fitting, etc)

if you are interested, i can get you exact part numbers and specs.


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## HydroLynx (Feb 17, 2018)

@Atomizer. Best thread ever. So much info crucial info here I need on proper root Oxygenation. So you say a thin film of water would not let enough gasses diffuse in and out? So the NFT notion that a thin film of water adds oxygen to solution, would you say that is unfounded?


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## Cold$moke (Feb 17, 2018)

Lol from hp aero to dutch buckets 

My experience with low pressure aero was enough to make.me not want to try hp.. 

dont get me wrong stuff grew great but at the time i was using advanced GMB. And it would clog sprayers 

The allure with hp is great as its just too freakin cool. 

But unless you got it set up just right 
Its just way too touchy lol plus alot more hands on with checking sprayers and everything else

I also didnt like the thought of not being able to clean out the pressure tanks .


This led me to rdwc. And its great but still requirse more energy and can be prone to root pathogens and other issues

So im going to do a side by side menicsus nft set up with my rdwc to see if it can keep up with rdwc. If it can i will be switching


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## Eskander (Feb 17, 2018)

HydroLynx said:


> @Atomizer. So you say a thin film of water would not let enough gasses diffuse in and out? So the NFT notion that a thin film of water adds oxygen to solution, would you say that is unfounded?


NFT troughs don't have much air circulation by design. You are trying to limit the addition of water to the air in the grow area after all. They have lots of surface area but in long troughs it isn't always enough by its self. Does kinda depend on how the plants a supported and if air can easily difuse in and out of those openings. For what I grow (habaneros), I start in rock wool plugs and then put those plugs into net cups filled with loose rock wool and top them with fine gravel. There isn't much air flow out of those and pretty much any humidity in the grow area is due to transpiration.

If you look at commercial NFT systems some of them get to 60 feet long and in those you have both nutrient and oxygen gradients from start to finish. In 8 foot runs, they are going to be fine as long as the return water either falls through the air into the reservoir or you have an air stone. Provided, of course, that your nutrient temps don't get too high. If you are growing pot, you are far better off getting wide purpose built NFT channels for plants like tomatoes than just cutting up a vinyl fence post. They have enough root spacing to the sides to not grow deep clumps and since the lid pulls off the rail, cleaning out the roots after harvest is a trivial task. Round bottom NFT is a very bad idea btw.

If your troughs are raised and the water can fall into the reservoir it also lets you add a few layers of pond filter material in between which will keep your reservoir clean and reduce your pump failure rate.


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## HydroLynx (Feb 17, 2018)

@Cold$moke yeah I tried those for years and it led me straight to DFT type systems


Thanx for your input Eksander. I actually have been trying a flood-n-drain style DFT (deep flow technique)

The thing I'm noticing with my system in square 8cm (3.2") pvc pipe, is that if plants get too large then the root mat gets compacted and they suffer more and more as they mature. I'm lately wondering if 20cm (8") diameter tubes instead can do the job for my sog style plants, along with a beefier pump to ensure the strong turbulent flow. Yeah so large tubes may be bad even for DFT, and I think you also said earlier in this thread the roots just clump at the bottom of round tubes, so then in my mind half the root mat gets cut off from fresh oxygenated flow. I have noticed at harvest that scum formed under the root mat on the grow-tube, even when I tried 1-plant DWC scrog to think if it. I also live in a hot place which doesn't help oxygenation.

The flood-n-drain style design applied to DFT is intended to give the roots some breathe time, but if a thin film of water around the roots, like say 1mm won't actually oxygenate like i thought it might, then what is the point of leaving roots dripping wet in air.

Although the one thing I love above this _flood-n-drain DFT_ thing I've been working on is that stagnant air gets pushed then fresh air gets pulled in every time the pump cycles on and off.


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## Cold$moke (Feb 17, 2018)

Im desinging and building a new system to go side by side with my rdwc after this run is finished.

In 15 years ive grown for about 3 years in coco
And the rest has pretty much been hydro of some sort.

Stated with waterfarm. 
Then dwc 
Then low pressure aero/nft in fence posts.
Then lowpressure aero/dwc with extra tall root chamber.
Now im on my 3rd rdwc design and i think i got.most yhe kinks worked out..and this will be my last setup for a few years .

But if the next setup comes close to matching the rdwc then i will switch.

I love the mad scientist aspect of hp aero and fogponics and rdwc. 

But take the coolness factor away and im charging my self to run air pumps and circulation pumps 24/7.


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## Cold$moke (Feb 17, 2018)

My new setup is going to be called a meniscus nft table.

Basically the roots are in a larger chamber where there is a very thin layer of nutrients film on a thin capilary mat.
Im also going to incorporate a way to circulate air

Where some roots will be directly in contact as more roots grow they stack up in the air

I love my rdwc. But this method might be better as far as operating costs ect.

There are pros and cons with every system and style.

I havent found one yet that id call perfect


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## Cold$moke (Feb 17, 2018)

What is DFT?


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## Budley Doright (Feb 18, 2018)

Cold$moke said:


> Im desinging and building a new system to go side by side with my rdwc after this run is finished.
> 
> In 15 years ive grown for about 3 years in coco
> And the rest has pretty much been hydro of some sort.
> ...


The only one I haven't done is RDWC and that was my next try but I'm thinking maybe not ........ not sure what to do . I'm worried about the roots a bit but I've covered all of my inlets wit silk screen which seems to work well.


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