why is my Ph going down

The Ph in my nft system is going down. I've been gone for 2 days. I left it at 5.8 and came home to 4.7. I'm using the Lucas formula. H2o2 my Rez temps do get a little hot 78 at the highest. But average is about 72. my Rez is only 8 gallons and I use 27ml of h2o2 should I use more? I also can't seem to find a water chiller that small. Here are pics of the plants right now and my grow system. Thanks for the help!!!! I hope everyone is having a good Christmas.
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First things first.

When did you last calibrate your meter?

Secondly for flowering when I ran hydro I would adjust slightly higher for flowering. Around 6. However even if you did this it would still put you around 4.9. Naturally pH lowers during flowering.

Thirdly has your ppm/EC/TDS increased during this time? If its increased then your feeding too strongly.

As EC increases pH falls due to a greater concentration of salts.


Merry Xmas.



J

Great questions, I have a blue lab gardian meter. It is spot on, the first thing I did was calibrate it. My ppm has only gone down 20 in the last 2 days but have drank about a gallon. The plants look healthy and that's why i'm so confused! Ph going down can indicate bacteria, but i'm using h2o2...

What are you using to buffer the ph of your solution?

And what quality water?

Ro water, when I do my Rez change with Lucas my Ph ends up around 5.7-5.8, then rises to about 6.2 and i add a few drops of Ph down to about 5.8 and continue this until next Rez change. I've never had it drop...it went from 5.8 to 4.7 in 48 hours! This is insane! I don't know what I should do. I guess a flush and Rez change will be first on the list, but that doesn't answer the question of why this is happening. I think a flush would only mask the problem.

Did you have h2o2 in the Rez when this happened?

Friedrice said:

Did you have h2o2 in the Rez when this happened?

Click to expand...

Yes, 25ml to 8 gallons...

Anyone else? Maybe as a precaution I should try some sm-90..

I had this happen too me back a while ago when I started cultivating with this method.
i wasn't using h2o2. All I did was change the Rez and wipe it down and it went back to normal.
Clean all pumps, sprayers, and stones.
Also start using black tubing if you haven't and run some water with dish soap through all your hoses.
I would also do a tiny flush.
Also if your ph is lowering it could mean your feeding a little too much.

did I help at all?

jondamon said:

First things first.

When did you last calibrate your meter?

Secondly for flowering when I ran hydro I would adjust slightly higher for flowering. Around 6. However even if you did this it would still put you around 4.9. Naturally pH lowers during flowering.

Thirdly has your ppm/EC/TDS increased during this time? If its increased then your feeding too strongly.

As EC increases pH falls due to a greater concentration of salts.


Merry Xmas.



J

Click to expand...

This is golden info right here. Exact same thing I was going to say

well H2O2 can fully burn out in 3 days

You know that if you can get your system to stay under 22c then you can just add a bunch of bubblers and stop using H2O2 unless you still find you get issues with root rot?