ok im finished i used electrical tape to place the probe wire along the inside of the rack and left the probe uncovered i hope the tape holds it I have 11 inch flexwatt back heat so the tubs will not be going over the heat tape and i set the night heat at 88 and day at 93. I guess i will see how the temps are tomorrow when i get home. The Herpstat seems to be working just fine. im useing unprinted news paper for a substrate i have a friend that works at a paper printing place, is that good for the substrate? I cant wait to get everything tuned in so i can put my balls in i think they will like it better then the tanks i know i will.