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Why would my PH drop ?

33 posts in this topic


 @Dapex how big is your res?.

From my experience the smaller res on the Lotus P1 or GT205 magnify any issues as you don't have much volume to act as a buffer. Personally I top up with half strength nutes, if I want to maintain a res ec of 1.2 I top up with 0.6 and add enough ph down to keep things stable-ish.. if you go down that route you'll need to kill any nastys in the res, I use stabilized hydrogen peroxide but there are plenty of options.

Even if you do stick to clockwork res changes its probably worth considering running a sterile system using inorganic nutes, grow media and h202. No organics means no bugs so less slime in the pumps, pipes and res.

I used to write down ec/pH/volume but with a bit of practice I already know roughly what I'm going to top up with before I get into my grow space, the ec/pH tests on the res just tell me by how much and which direction my guesstimations were out.


You seem to be doing a cracking job so far, keep us posted as to how you go  :yep:


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Still seems to be getting worse.  
did fresh water change.  PH 6.0 ans EC 1.2. Within 24 hours the PH was 5.6 and EC was 1.5. 
adding tap water does keep the PH at 5.8 and the EC at 1.2 BUT I haven’t had to top up like this through this grow.  All through veg and the first 3 weeks of flower I let her drink the water and the EC and PH stayed kinda stable.  

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Looks vaguely similar to the issue I had, in a poor lighting and out of focus kinda way :hippy:


Your last photo v mine.



If it is a similar issue, then I don’t know the answer yet, but mine maybe pointing towards leaf temps. It’s been a fight getting the balance of air temps and water temps right. LED are a bit of a pain atm. Are you 100% power on your lights?


Last throw of the dice is what type of PH- down are you using? I had trouble stabilising mine until I switched to phosphoric and nitric acid.


Hope you find the cause after sorting the EC out.

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