ph been dropping with low ppm... did a rez change been kinda of steady around 6.0. It dropped back to a 4.5 after about three days. Mixed stinger nutrient solution and just topped it off. Temperature a steady 74-75 degrees. Rez temp around 66-72 seems to not be drinking much either. Humidity has been a lil high around 70% lately but dropping to 60% now.Anybody know what’s wrong?