pH Problems w/ first DWC

[closetkush]

I just setup my first DWC grow last night and dialed-in the solution to a pH of 5.7. A few hours later I decided that I would re-check the solution and the pH reading was 6.0. So, I recalibrated my pH pen and checked all of my buckets once more and added more pH down to get it back to 5.7. I just checked again and the same thing has happened. All of the buckets are reading 6.0 - 6.2. So, I recalibrated my pH meter again and checked and got the same thing. So once again I added more pH down to get it back to 5.7, recalibrated again and checked all of the buckets. Seems stable now, but who knows what I'll find tomorrow. Is this normal? Does it take a few days for the solution to stabilize or maybe the plant absorbs nutrients causing a change in pH? I thought once you set the pH, then that would be that. Also, I'm using a CWP Instruments Accurate pH pen(which I don't think is very accurate at all since I have to recal it after every damn use and it fluctuates), the CWP pH4 and pH7 cal solutions, and General Hydroponics pH down. I'm thinking of buying an Oakton pH2 and maybe some different cal solution, but I don't know if this will solve my problem. Any ideas or suggestions???

 

[budm]

What size res? What nutes or additives do you have in the res? Are you using RO or tap water? I noticed pH swings with FF nutes in my DWC, but when I switched to the DM line my pH became stable as a rock.

pH is a great indicator of what's going on in the res as well. it will change a little as the plants feed, but it can also be an indicator of root rot issues or decaying material in the res.

 

[closetkush]

5 gallon buckets with tap water(8.2 pH, 285 ppm), AN Sensi Grow A and B, Botanicare CalMag+, Nutrilife H2O2, and buffered with GH pH Down to 5.7pH and 600 ppm.

 

[budm]

It seems your water is a little on the hard side and that can play a factor in trying to get things stable. If you don't have a RO filter available, try picking up some Distilled water and I bet you see things levelling off.

 

[closetkush]

Thanks, yea I was thinking that could play a part in it, but I was also wondering if it could be algae or something similar growing in the solution? If so, what would take care of that? I'm using the H202 which is supposed to help, but I was wondering if Hygrozyme or something else might help as well. As of right now, I'm still buffering the solution on a daily basis, which can get expensive having to buy pH down all the time.

 

[budm]

What are your res temps? Algae, dead roots, etc can make the pH swing - how do your roots look? Have you lightproofed your buckets?

I almost lost my first DWC crop due to my res temps getting out of control and root rot setting in. The plants looked very wilted looking and there was brown slime in my res. After a few hours of searching, I stumbled upon a thread for 'Heisenberg EWC tea'. Very long thread, but some great material covered in it. The short version is you brew a compost tea and introduce beneficial microbes into your res. It saved 5 out of 6 of my plants! If you can't keep your res temps below 68, then you may want to use beneficials. Between the benies and different nutes, my pH is as stable as a rock now.

In any case, good luck & let us know your outcome.

 

[closetkush]

Ok, so I've done a little research and I have a new game plan. I'm starting to notice some yellowing of the lower leaves on my Strawberry Haze and Hawaiian Snow plants, so I'm trying to act quick before it gets out of control. I'm gonna stop using the H202, and get some Hygrozyme and some Orca(liquid mycos) and see if that will help. My pH is usually around 5.8-6.0 and the ppm is only 650. I'm swapping my photoperiod to 12/12 on Tuesday and will begin this nute regimen:

AN Sensi Bloom A & B
Botanicare CalMag+
Hygrozyme
Orca
GH ph down

My questions are, will the ph down harm the Orca or the Hygrozyme? Will I need any Carbo Load or Molasses?

 

[closetkush]

Oh, and to answer your question about my roots... they look healthy and bright white. I'm using Lowe's dark gray buckets with black 6inch net pot lids. I don't think any light would be penetrating unless maybe through the cracks in the hydroton or the quarter inch hole where my air line enters the bucket. I can just put some tape over that I guess...

 

[Kush Killer]

not to jack ur thread but i also have the same problem, except i notice brown slim or residue or alge of some sort in my res. i cehck ph 3 times a day 7am, noon, and 7pm everytime i check it its @ 6.8-7.0 ph down to 5.5... im using r/o water with humboldt nutrients, (3part,dark enegry,prozyme,micro zyme,ST,cal/mag, white widow powder,and humboldt roots. at first i assume it was residue fro some of the "brown" additives, or possible the powder white widow.. but idk.. gonna do res change and clean everything out tonight.. to me my flucation seems a lil be out of control..

my res is completly light proof, temps between 64-72 on average about 68, rh is at 65% tent temps are 68 nite 78 day give or take a few degrees at any giving time..

 

[TorturedSoul]

Tap water? Are you letting it dechlorinate fully first? Otherwise, it's happening in your reservoir which may be changing the pH. Aeration can do the same to some extent - and also speeds the dechlorination process. So... Try filling an open-topped "pre" reservoir with your tapwater and aerating it well for a few (12 is great) hours prior to using.

And yes, the pH of your solution will rise as plants consume parts of the nutrients - but it's generally a gradual thing unless your reservoir is too small for the size/number of the plants it is expected to support.

 

[Kush Killer]

I have a 10 gal res