Yeah I though of that I may not have individual controls for each tank but may split it into 3 columns (at 10 high each column) or something along those lines and anything that has special heat requirements will have its own heating system most likely flexwatt. that way I can have the minimal amount of energy used to properly keep my animals. I will definetly build in several safeties so I don't cook my animals. I am trying to find some sort of solenoid I could use inline which I will hook to another t-stat which will activate at 90 degrees or whatever I need at the time to close a valve in case it gets too hot that way it will bypass the racks and go back to the holding tanks.