I would first double check your pH meters calibration to maintain accuracy and continue to readjust the pH of your Waterfarm to pH 5.8.Yea, bringing this back. New hydro grower here and just got a waterfarm. I've had huge PH swings during germination from just plain water. Drove me nuts and GH, of course, said my water quality is causing the problem. I read a grow journal here and the guy had a waterfarm and had the same problems I had. Long story short...I googled "PH issues with hydroton" and was shocked at all problems guys have with PH rising from hydroton. Waterfarms use a lot of hydroton in a 2-gallon res hence the dramatic increases in PH. An expert claimed that rinsing hydroton in a 2:1 water and vinegar solution helped stabilize it. I simply rinsed it in water until there was no residue left; a newb mistake. All that said I'm 2-weeks into veg and my PH increases about 1-point in about 12-hrs. My TDS is about 450 PPM. I'm adding 1-1/2 mil of PH down twice per day to keep my PH around 5.8. Is adding this much acid to my res going to hurt my girl? She looks fine and growth is consistent.