The pH game

I grow DWC and have for the past 2.5 years. Im finding, especially late in flower that im chasing the pH around.

Every day I check and adjust about 3 hours after lights turn on and everyday its about 6.5 on my heaviest feeder after setting to 5.8.

I've tried everything to adding more nutrients to adding less and im stumped. Adding less seems to make it rise faster(consistent with what i've been reading) and adding more makes it slower but then EC increases to a point where it burns the plant. So clearly this is a feed thats too much or my humidity is too low and the plant is drinking more water? Humidity is about 40%, but im week 7 of 9 and dont want it too high.

I usually set EC to 1.2 and it drops. So I set EC to 1.3 and it rises. Its like wtf is this plants problem. Never had so much issues with a particular plant. Does it want like 1.25EC or something cause my meter doesnt do hundredths.

The daily PH adjustments are getting old fast. Its bad enough I have to change out the res every 3-4 days.

I've read up on ion exchange and when plants take in more cations the pH will drop and more anions the pH will rise. So if thats the case shouldn't I be getting a pH drop since in flower the plant is taking in more P and K than N.

Switched mid grow to H16 nutrients, but was having this issue with Ionic and Dynagro as well.

I use tap water, EC is .16 (80ppm 500 scale) but the pH is right around 10.0 and after setting the nutrients the pH is around 6.0 which I like about the H16 that I dont need to add a lot of pH down to bring it down.

Plant is healthy and roots are even healthier before anyone mentions slime. Roots have almost filled the 5 gal bucket and they are still white. I know thats not the source.

Im thinking of switching to undercurrent so I can have a bigger res and more stability as I hear this is an issue with 5 foot plants in a 5 gal bucket that really only holds 3 gallons of water.

Any opinions? Links to some good reads on it? Google doesn't help me. Just hear the same shit oh your plants are hungry, feed them more. Even when I do to the point of overfeeding I still get a rise, albeit less of a rise.

Last night I refilled the res because the last half gallon was 6.0 at 1.4EC. So the pH was still rising as was the EC.

pH of your tap is 10, so as your plant eats the water goes back up

try with more pure with water pH near 7

I was thinking this as well. I didn't find myself chasing pH as much where I was growing previously which had awesome water. Same low 80ppm but with a 6.7 pH.

Maybe i'll steal some water from there for a bucket and test this out.

I mean it makes sense as the water is 10 and once you add food it drops so naturally once that food is eaten it will rise.

firsttimeARE said:

as I hear this is an issue with 5 foot plants in a 5 gal bucket that really only holds 3 gallons of water.

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I think your doing everything correctly and isolating your problems on your own.

The solution isn't limited to an undercurent setup though. Just use any setup with larger reservoir.

- Jiji

"I mean it makes sense as the water is 10 and once you add food it drops so naturally once that food is eaten it will rise."
I like this part...
I use an ro filter, seemed to take out all the extra variables.
ph is 7.0 and ppm is 10-20 out of the filter.

Hey firsttimeARE a buddy of mine had the same exact problem and we found out that the chlorine in the tap water wasn't evaporating fast enough. We let the water sit for a extra day to get all the chlorine out. The ph was more stable.

Sent from my SM-G900P using Rollitup mobile app

a bigger res also helps in keeping ph more stable fr bigger plants

i found high alkilic water will tend to rise back near its original ph.
i would suggest just trying a test with a different water source on one plant and see how it reacts compared to another with ya tap water then u will know for sure if its ya water make sure ec is set at same for both buckets as is water level.

hexthat said:

pH of your tap is 10, so as your plant eats the water goes back up

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good info there mister/missus