Hi, I have been using this cloning system for about a year now. And with the exception of some heat issues last summer, I have been getting great results. Until now. For the past few weeks, I have not been getting any cuttings to root. Some stems are rotting, some are getting hard and brittle. I cleaned it good, no help. I bought a new rubbermaid tub and for about 10 minutes ran bleach water through the pump and sprayers using a lid with no holes. And temps are staying between 65 and 70 or so. STILL, every day I get the PH to 5.8 and within 12 hours it has gone back up to about 8. What am I missing? I sure could use some advice.