Hi all,

Apologies if this has been covered already - I can't find a post/thread with this issue.

This is my first DWC setup. I'm using a 20gal Rubbermaid tub with three air stones in the bottom. I'm using tap water, no nutes, and a Hanna meter and calibration solution.

My problem is that PH fluctuates wildly. I can adjust the PH down to 5.5, but it will climb back up to 6.5-8 within 24-48 hours. Other than the air stones, there's nothing else in the water, and the water does not touch the net pots.

I have been using white vinegar to lower the PH. Does PH down work better? Any other suggestions on what is causing my PH to climb so rapidly or what I can do to keep the PH in the 5.5-6 range?

Many thanks!