I'm running a simple DWC system with air stones. It's a 12 gallon container that I'm filling about halfway with nutes and water. I have a separate container that I mix up the solution and let bubble overnight. Someone suggest that I try that to stabilize the pH. I'm using RO water, roots organic Buddha grow, advanced nutrients mother earth super tea, and cal mag. I'm still in the veg stage. I mix the solution and pH it to about 5.2 with general hydroponics pH down. I check it the next day, and it's stable, not a big swing in pH. PPM varies, but it's usually under 500. I take my old solution in my dwc resevoir and change it out for the fresh one. If I check the pH in the res a few hours later, it's already risen. It will rise to over 6 in a few hours. Ill add more pH down to the reservoir to get it back down. I'll check the next day and it's up over 7! I can't seem to maintain a steady 5-6 pH range. My plants are really suffering for it too. It's just random bag seed, but they aren't looking good. I posted pics in a different thread and everyone says its pH issues. What could be causing the huge swings in pH, and how can I stabilize this a bit? Any help would be appreciated!