I'm building a rack this winter to be able to get ready for buying a new breeding pair in the spring, and I'm wondering how everyone sets up their heating to get a heat gradient.

I have a 15 foot package of ZooMed heat cable (but thinking of just going with heat tape instead) and can get more, but I'm wondering, do you just run it under half the tub to provide the warm side and keep the ambient temperature of the room at 80 or do you run two different ones with two different thermostats so that the ambient temperature of the room doesn't matter?

I'm new to tubs, sorry for the noobish question