First off, want to thank everyone who has responded. I know I've had a lot of questions but the more we experiment, the more questions we have, lol. Just want to get it right. Anyway, in securing the thermometer and thermostat probes to the glass inside the tank above the UTH, I read somewhere that mounting putty (nontoxic) can be used, others have used tape flush to the glass. Some people say however, these are not safe that simply putting a weight (rock, pebbles) on top is the way to go. Anybody with a strong opinion on this?