DWC experiment not going great!!!!

After a few months of successful growing in coco I grew (no pun intended, lol) tired of getting bags of coco soil delivered to my door, the same fedex guy everytime and the nosey twat was sayin "god thats heavy, whats in it?".... then there is getting rid of it once its finished (I still have a few bin liners full to dispose of upstairs).

Anyway on to my bubblers, i did a test run with 8 in a large flat tub with lid but i was using hard water straight from the tap, so I realized i needed an RO water filter, it gave me water at around 15ppm (down from about 450ppm), but im not getting the explosive growth that I expected to see from this type of system, I mix the nutes as suggested on a chart I downloaded, this gave me around 550ppm which from what ive read is too high for young plants, it also looked like i was getting nute burn (see pic attached), so I changed the water and gave them water with nothing added (except ph down), but after a few hours the ph had shot right up to around 7 (im guessing no nutes means no ph buffer), so I added a very weak nute mix which gave me around 180ppm.

Here are the stats....
air temp = 75 - 80f
water temp = can get upto 25-26c
Nutes = Canna aqua vega, rhizotonic
Ph = 5.8 (but gradually climbs to 6.0+ after a few hours, ph down being added every morning and evening)
ppm = 150 - 180
light = 250w blue cfl
20ltr storage tubs with lids

Anyway if anyone can offer any advice on whats goin on, or if i can use diff nutes for better results I will give it a bash, I previously used ghe in soil and it was ok but had huge salt buildup.

Thanks in advance!!!

ps. 1 other thing, im using 80mm net pots, does this restrict the size of the plant? Cos the first time round they only got to about 10 inches tall then just stopped getting taller, i wondered if it was because the roots where moving around in the bubbles straight out the riot cube, whereas in larger net pots the first inch or so of root would be going through the clay balls!

Are you adding calcium and magnesium.....when using ro water you need to add calcium and magnesium along with your regular nutrients...your plants are probably suffering from a deficiency

Cal-Mag

It is needed whether you are using hard water or RO water. I found this out 1st hand. It is an absolute must.

Just for the record, I used RO water at 1st, but then switched to (hard) tap water (300+PPM) and guess what? NO DIFFERENCE! I expected it to be a problem, but I found out that the RO advice was a bunch of hype. Really, I did not notice a difference at all.

That being said, by the time I add my nutes and the Cal-Mag, my PPM is much higher than I have seen people around here suggesting. I keep my moms at about 1200PPM, rooted clones at about 800PPM and in flower I start them at about 900PPM but then get up over 1500PPM (around 1800 even). Never had a problem and I have come to these conclusions, methods, numbers, based on experience. Much of it seemingly contradicts the accepted norms around here, but results speak for themselves.

in any case, it sounds like you need some Cal-Mag and once you have that I would go ahead and increase your nutes/ppm a bit as well

The reason I use ro water is not because I thought my plants would grow better but because of ph fluctuations in my reservoir when using tap water....now I rarely have to worry about checking my ph as frequent as before......sometime i go a whole res change without much fluctuation......

Thanks for all the replies but im left a little more confused, when I read up on hard water it seems it already contains calcium and magnesium and the filter removes these elements, so i use the RO filter to remove the TDS then I re add them afterwards!!!

I read this info
http://waterquality.montana.edu/docs/homeowners/tds_fact_sheet.shtml
the 3rd paragraph entitled "What is hard water?"

And being in the uk i cant get cal-mag but I can buy the single element supplements individually so I guess these are the same!!!

1 other thing, is their such a thing as too many bubbles? I have a 4 outlet pump which can kick out 2.5l of air a minute on each outlet so I put 1 airstone on each and when the valve is fully open the roots are moving a hell of alot, i tried it out on a lower flow so the bubbles were just a gentle stream of tiny bubbles and it didnt seem to make any difference to the plants so can anyone recommend which will be best?

Thanks again everyone.

the hard water is not your problem. How many gallons of water are you using? How low under the net pots is your water level? What type of air pump are you using? some tend to overlook these issues. I hope to make a thorough thread about water level/gallons per tub. If say you are using a pump that pumps 7.8L you can only really work with close to 2 gallons of water. 3.78 Liters= 1 Us Gallon 3.78 * 2 = close to 8. Anything more as far as water will suffocate your roots. You are using a 2.5L pump, but that is not enough for a 3.78L Gallon of water. UNLESS you have a good root/oxygen zone or a pump that handles more than 7.8L or 2 US Gallons. Keep that water level 2-4 inches below the bottom of your netpot. I have a strong feeling this is your problem. Hard water means you don't need Cal-Mag because it is already present. 2.5L is enough air for 1/2 Gallon of water. Remember a Gallon of water needs at least 3.78L Airpumps to compensate for oxygen:water ratio. I would upgrade my pumps or add another 2.5l to make 5L worth of pumping air. if I were you and lower my water level. If you cannot afford the pump for now just lower the water level. The bubbles creating an aero ponic mist is what is going to help your plants grow in DWC. The more water the larger the plant, BUT your airpump needs to be able to compensate for the weight of water and be able to pump enough oxygen to the roots. . GL

On the bit about to many bubbles m8y the more bubbles the better. I used a 6 way air pump on 1 plant and it loved it the plant turned into a monster 6 ounces dry from 1 plant which isnt bad for me n only had a 400w hps which i used the whole way through veg and flowering. And the plant was ice from nirvana. I always use tap water my ppm is 200 ish when i run it n ph stays stable 5.5 ta 6.1 it guzzled it like it was a virgins piss so i dont think all this useing RO water isnt worth the hassle n extra cost. And the size of the net pot dont matter, i always filled mine 1 inch above the bottom of the pot but like i said id 6 air stones in there. And whats up with ur plants to me they lookin like they on lock out mode maybe it was the over feeding ya gave them or maybe like the other guys/ladys said ya need some Calcium n magnessium after useing ro not to sure never used or read up in depth about useing ro.

The tubs r 20litres and i have drawn a line at the point were it has 15litres in which is were the netpots just dip into the water, they have had a fair drink in the last few days and its dropped to around 14 litres so its prob only about 1/4 inch above the water, i have a 2nd pump with 4x 2.5 ltr per minute outputs so i may split the tubes off and double the output to each tub to 10ltres a minute an see how it goes, im kind of bummed out i invested in the RO filter now which was the advice i got on a diff thread and to quote "you are givin them some nasty shitty water if its at 450ppm already, get yourself a RO filter, it stopped my nute problems over night...."

So yet more contradicting opinions to think about

You have a calcium and mag deficiency,ro process removes calcium and magnesium like you mentioned,it is apparent that is your problem from the pictures you provided.....you can order cal/mag online no matter where in the world your at.....but you must have it...............and don't be upset the ro filter was a good investment,any serious hydroponic grower will attest to that,just get you some calcium and magnesium however you can and bump up those ppms because your plants are definitely in need of nutes........and the more bubbles the better

freerider said:

Thanks for all the replies but im left a little more confused, when I read up on hard water it seems it already contains calcium and magnesium and the filter removes these elements, so i use the RO filter to remove the TDS then I re add them afterwards!!!

I read this info
http://waterquality.montana.edu/docs/homeowners/tds_fact_sheet.shtml
the 3rd paragraph entitled "What is hard water?"

And being in the uk i cant get cal-mag but I can buy the single element supplements individually so I guess these are the same!!!

1 other thing, is their such a thing as too many bubbles? I have a 4 outlet pump which can kick out 2.5l of air a minute on each outlet so I put 1 airstone on each and when the valve is fully open the roots are moving a hell of alot, i tried it out on a lower flow so the bubbles were just a gentle stream of tiny bubbles and it didnt seem to make any difference to the plants so can anyone recommend which will be best?

Thanks again everyone.

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I was using RO water and I had the same exact problem you are now having. As soon as I added Cal-Mag, the problem was solved (I tried everything else and thought it was everything else).

As for hard water also needing a Cal-Mag supplement. I don't remember the thread, but someone on here broke it down and explained in detail why even hard water needed a Cal-Mag sup. without being able to explain it on the same level, I will break it down in layman's terms: basically the plants are not able to use the Cal and Mag that's in the hard water, so you have to add your own. something about it not being broken down in a way that allows the plants to uptake it. wish i could explain it better, but the guy made perfect sense and results speak for themselves. maybe its something like a lactose intolerant person needing to get their calcium from something other than milk. lol

as for bubbles...the more the merrier. DWC is great. super easy. just make sure you've got a lot of bubbles. you can get a 950gallon pump from: http://cheaphydroponics.com/store/view-all/sunleaves-durapump-air-950gph/prod_500.html for only $35. they work great.

and i have tried every air stone known to man and nothing works as good as these (from another site, sorry): http://www.hydroponics.net/i/134029

anyhow,your problem will more than likely be resolved with some Cal-Mag. that's the 1st thing i would look for if i were you

well mate im using the exact same as you canna aqua and dwc using ro water all i do is mix tap water and ro water 50/50 my ph is always stable 5.8 to 6.1 and they are drinking it like fuck growing like they are on steroids

Thats good advice Cissy thanks, I will invest in some calcium and magnesium, I know from past experience that if u skimp on quality your end result suffers so now im glad i got the RO system, a store i use alot sells cal and mag so i will order some!

Thanks

I still aint getting much joy, I got some cal-mag, added it in, and the plants did perk up a bit, the colour darkened quite well, and they seemed to be stretching up for the light more, but as for growth..... well non, do they need recovery time or something?
I found the rez was getting too warm, upto 78f, so I did some reading and and 1 guy was just putting frozen water bottles in the rez to lower the temp, now its usually around 68f and sometimes even lower, again this seemed to pick em up a bit but STILL no explosive growth, they are very small at only 10" tall.
Any more suggestions?????
air temp is always around 75f, good air circulation etc!!!

How high you got your ppms.......by now you should be between 450-700 ,it varies with strain........some strains suck up nutrients like crazy....my little sour d plants luv their nutes...ppms at 900- 600ppms of pro grow and 300 ppms of cal mag.. and no sign of burnt tips and or weird growth......

Seedlings, Early Sprouts 100 to 250

Early Vegging 300 to 400

Full Vegetation 450 to 700

Early Blooming 750 to 950

Full Mature Blooms 1000 to 1600

Well i am using canna aqua vega and i downloaded a chart which said to use between 1.5 - 3 ml per litre for new clones, and 4ml per litre of rhizotonic, which gave me around 800ppm (i used the lower amount of 1.5 to be safe), now they have been in a little while i upped the dose to 2ml of vega, also added 2ml rhizo as suggested, then added a bit of cal and mag for good measure which bumped my ppm to over 1000.
The strain is super skunk, i recently started some white widows also, they have shown no growth yet but roots r forming quite nicely so i guess these r just finding their feet.
Its hard to get the balance right cos u read so many diff opinnions, i guess it may be just trial and error.
Incidently the skunk is showing what appears to be nute burn, light brown tips and some down the sides of the leaves, it could be defficiency tho, its hard to tell

Barely rooted clones should have a ppm of around 200ppm.....800 is too high......the hardest part of growing is diagnosing toxicities and deficiencies........it sounds like your skunk is is suffering from nute burn.........good luck,.,.,.,. hopefully you get things dialed in.......

I'm not using any Cal Mag on my tap water tote, and I see no signs of a def yet.

Cesaro said:

I'm not using any Cal Mag on my tap water tote, and I see no signs of a def yet.

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Uhhh ok..........and why did we need to know that.......

jcdws602 said:

Uhhh ok..........and why did we need to know that.......

Click to expand...

Are you serious fucking serious? The OP is talking about a problem with his plants, people are mention Cal-Mag as the problem, soem are saying otherwise. I am pointing out that I'm using TAP water with no Cal-Mag, so maybe his problem isn't cal-mag? I thought it was obvious? I think getting peoples input from various sources is a lot better than not? ISn't that the entire point of this board?

Do you make it a habit to just single out posts, and ask people why they posted it? Are you like a reverse mod?

no i am not serious fucking serious ..........Sorry bro dont get all puffy ...........good insight.......hehehe.........any more pics??