When I mix my nute solution, I set the pH to 5.8. After 24 hours in the res (DWC Setup), the solution goes up to 7.0, and no matter how hard I try, I cannot get the pH to stabilize at anything lower than 6.7. No matter how much pH Down I add to the res, it will always go back up to 6.7.

This only happens when the solution is in the res. When I mix my solution in a spare tub 24 hrs [in advance, I can set the pH at 5.8, and it will stay at 5.8 until I add it into the res. Then it jumps up to 7.0 within a few hours.

How is my plant causing this pH change? I washed all my hydroton in advance. How can I get the pH to stabilize at 6.0?
samusx Reviewed by samusx on . My plant is somehow raising my pH uncontrollably... When I mix my nute solution, I set the pH to 5.8. After 24 hours in the res (DWC Setup), the solution goes up to 7.0, and no matter how hard I try, I cannot get the pH to stabilize at anything lower than 6.7. No matter how much pH Down I add to the res, it will always go back up to 6.7. This only happens when the solution is in the res. When I mix my solution in a spare tub 24 hrs [in advance, I can set the pH at 5.8, and it will stay at 5.8 until I add it into the res. Then it jumps up to Rating: 5