Thanks for the add.. This is my first hydroponic grow..I'm starting up a five gallon bucket / top feed...I put in my nutes / PH to 5.7....Came back after the dark phase and tested PH and it was 3,5...Check calibration of meter ...Re checked PH 3.2...Add 1.5 mil of PH Up re checked PH and it was 7.2 , checked PH with a PH dropper test kit and it's was a correct measurement of Over 7.0...So I removed sprouts from grow bucket....This morning I checked PH and it was 6.4. ...Nutes used, Flora Series from GH / add Hyrdroguard all at quarter strength...Question : how do I control my PH fluctuations...? And how to store Rapid Rooters, I've got a tray of 50 and need only 2 ..?.Thanks