I'm trying to think of a way to keep my belly heat temps more even... with a UTH on a glass tank w/ bark substrate it varies a lot based on the substrate depth, which worries me. I was thinking of putting an 18x18 or 18x12 piece of tile at the warm end of the tank (40B) under the hide. This way the UTH is heating through the same material/thickness so the temps should be much more even. I should also be able to turn down the UTH temp overall, which should save electricity and be safer. Also hoping that this might help the heat to radiate through and warm the air more.

Thoughts? Which would you recommend, vinyl or porcelain tile? I'm swinging by Lowes after work to check out their selection.