PH keeps moving up

[Newdwc]

Hi! Hoping someone can help me out. This is my second run and I’m learning a lot. I run a current culture 40g rdwc system and use the full line of cyco products. I fill up my res with 40g of R/o water and my water out of the faucet has a PH of 7.2, add my nutes (carefully measuring everything). I then use cyco down and bring my PH to 5.9. I do a full water change in 20 min using the pumps to remove the service of water and add the new mix. After 12 hours my PH is back to 6.4. I’m in the 2nd week of veg and would like to keep the PH between 6.0-6.3. My temps are 68-70c and my water temp is at 68 degrees. Can someone with more knowledge than myself please tell me why my PH is going up so fast and what I can do to fix it. THANKS!!!

 

[Rheaun]

There's a few things that affects PH and the last thing to consider is the plant uptake and exudates. If you use an airstone the nutrient solution may be getting too much air/oxygen and could be oxydizing nutrients. I aerate water before mixing but no longer aerate mixed nutes. Also starting alkalinity of your water may have elements of high ph and be too high PPM for your EC. Hope that points you in the right direction, I'm just starting to get a grip on this subject after 6 months of learning.

 

[Vegan4life]

I would be more worried about your "68-70c" temperature...

 

[Newdwc]

Thanks for the reply and I’ll try turning down the air going to the stones.

F