Taking advice from my breeder as well as some others here is what I did. I have a 20 gallon long tank for my BP. I bought two UTH/heat mats. Together they cover a big majority of the bottom of the tank. I keep one set at 80 and one at 89/90. My breeder keeps some enclosures this way and says as long as the ambient temp in the room is above 70 degrees she does not add any other heat. Doing that, my ambient temp was staying about 72 degrees and the entire floor surface of the tank was 80 or higher. I did add a very small CHE this winter ( micro sized one, only like 25 or 40 watts I can't remember which) with that running on full blast it keeps the ambient temp at 78-80 degrees. In the summer that room stays warm enough I won't run the CHE. it does lower my humidity so when I see the eyes cloud up I turn the CHE off to get the humidity back up.