I am trying to help out my son and have been reading through the threads, but have a question. He just switched from a 10gal tank to a 26X18X7 sterlite tub. He will be working this summer to buy or build an enclosure/rack. We are having difficulty getting the temp stabilized. We are using a 25w cable. Even on the lowest setting the hot side was 95.8. I switched this morning from a Zoo Med rheostat to a Home Depot Dimmer, hoping that would help.

Currently, the cable is attached to the bottom of the tub and we are using Aspen substrate. Our house temp is 76/77. Do you think we should attach the cable to a ceramic tile or something else and sit the tub on it instead of attaching directly to the tub?

Any suggestions would be appreciated. Thanks!