So the t-rex and ultratherm heat mats are more reliable than the zoo med one? If i were to just the heat tape, how much of it would i need and where would i place it on the tub?
I use the Zoo-med UTHs on a thermostat... As a general guideline, you want to have about 1/3 of the bottom of the tub covered. You want that 1/3 to be on one end of the tub so you can offer a heat gradient from the warm side to cool side.
Oh, and as far as the adhesive, you can use foil tape to mount the UTH to the tub rather than peeling the cover and using the adhesive on the UTH. By using the foil tape, you can easily remove and reuse the UTH without risk of damaging it.