pH problem in dwc

[redbeard]

30 gal recirculating top fed dwc . 3 18 gallon totes 1 for res other 2 1 plant each . 4 weeks in flower gh flora trio hydra guard and calimagic. After water change hard to stabilize ph takes me 3 or 4 days to keep it the same . Say I check in the morning make my adjustment then check in afternoon and I'm good . Next morning low . After a few days gets evened out. Then when I change over again . What am I doing wrong.

[Skippy]

i don't think you are doing anything wrong per say. If i had to guess the root balls have a different PH than your res so it is changing what you are putting in. therefore it is taking a few days to level them out as best you can. then when you do a res change you are starting the process over again. I tend to let my PH wander and let the plants decide what they want. as long as i stay between 5.5 and 6.5 i do not adjust i let it level out on its own. If it drops too low i will boost it a bit with PH up or some Armor SI but then you have to give it some time to circulate and mix between your res and all root balls etc etc. I would pay attention to the PH of the solution you are taking out on res change day and do your best to put the new solution in at that same PH as long as it is in range of course. this should hel level things out a bit fast for you.

Either that or change to a Nutrient regiment that will stabilize the PH automatically. I have tried the AN PH perfect line and it does work however it keeps you dead on a ph of 6 without any wandering and honestly the plants like the PH to wander within range of course.

[POKEDSMOT]

When I change my res I let it run for an hour before adjusting the pH. This allows the pH buffers in the nutrients two activate. Usually I don't have to do anything. If I do it pH up. I try to get as close to 5.5 as possible but don't get too neurotic over it. Close is good enough. Usually by the next res change it has ranged up to 6.0-6.5. You shouldn't try to keep your pH at one specific number you will end up add unnecessary chemicals, and Nutrients absorb at different ranges. Also I check pH at the same time twice a day.

[Jason]

Do you have an air stone or two in your res?
If so, the 02 will move your pH up.
I adjust mine down to 5 ish and let the 02 move it up over time. Sometimes that can be just hours, I check three times a day and add balanced tap water to adjust down.
I'm at Week IV of the GH Flora Trio schedule. I'm adding .25 to .5 gallons of H2O per day to each of my two gallon Water Farms.
I let pH range from 5 to 6.5.

[redbeard]

Thnx to everyone on gwe for all the help . Didn't think about the root mass still being wet and the possibility of it having different pH . Makes sense ,so no didn't have airstones in res but do now 2 in each tote but u can't even see em anymore . First try at dwc got the last of my clones from old seeds from outdoor days going at my Bros place it's the dwc and I'm going in the dirt. I'm couple days from water change so it's stable know. Thnx again .