PH issues with rez

Im having problems with keeping my ph down, and looking for suggestions. I have been fighting this from the start (2 + years)

I am running a recurlating nft, stinkbud style, with a 11gal sterile res, with air stones. and jacks 321 nutrients. With no other suppliments.

My tap water runs about 300ppm, and a ph around 7.0-7.2. About a year ago I installed a RO/DI system to try to help lower my ppm/ec. The RO is running about 8ppm and 6.8ph

Since then i have tried everything from 10% RO all the way to pure RO, and still cant keep the ph down.

I Gen Hydro ph down, at night I can drop it to 5.4 and by morning it up to 6.4 range, and by night back to 6.8-7.0 .. i know RO removes the buffers for ph, but this even happens with straight tap.... i have also tried adding ph up. To 10.0 (after nutes) then ph down to 5.4ish, and still does the same.

I have also tried to just let it ride at the 6.8ish range and started suffering lockout.

Trying to find an addmendment, to help with the swings, and that wont clog my nozzles.

I was thinking maybe fulvic, or humic acid. But not sure.

Ditch the air stones.

MisterKister said:

Ditch the air stones.

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This.
Just drop a pump into rez to recirculate water, any ripples on the surface of the water draws O2 into it.

Thank you all!!! Ditching the stones tonight to see if that helps

You need to use a bisulfate acid buffer, it's the secret sauce to getting a nice stable pH.

auswolf said:

You need to use a bisulfate acid buffer, it's the secret sauce to getting a nice stable pH.

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What brand bisulfate acid do you use? If I may ask. I did a search on Amazon and it came up with pool ph up/down and said sodium bisulfate is that the stuff you are talking about?

Treesomewanted77 said:

What brand bisulfate acid do you use? If I may ask. I did a search on Amazon and it came up with pool ph up/down and said sodium bisulfate is that the stuff you are talking about?

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Yes sodium bisulfate is the stuff, the brand I use is seachem acid buffer. But if your using ro/di water you will need sodium bicarbonate (alkaline buffer) as well to create a buffering system.

I use Mono Potassium Phosphate (MKP) to stabilize my water. I use it during flower anyhow, and it works for me. But I use tap. RO was a waste.

ZeroSkill said:

I use Mono Potassium Phosphate (MKP) to stabilize my water. I use it during flower anyhow, and it works for me. But I use tap. RO was a waste.

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How much per gallon do you use?

Any update on how ditching the air stones worked for you?

Potassium Silicate or Calcium Carbonate will help(something like Calimagic).

I personally like potassium silicate(15-30ppm Si) as a pH buffer in hydro. Very easy to use and dirt cheap.

Sodium bisulfate sounds interesting. Might give that a go in the future.

gfiles77 said:

How much per gallon do you use?

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Sorry took so long to reply.
I use for final flush 1.5g / gal MKP, .8ml / gal fulvic.
for normal planting, I use
.5 g / gal on veg
1g/gal flower