i have about 1 inch of substrate on my UTH izzy pushed all of it out in her hide so shes layign right on the pad. pretty cool.. think i might switch to coconut dirt from repti bark tho to help with hummidity.. and thx for all the replies.. so did some thinking and 3 feet is much to big im thinking 18to 24 high is sufice.. what type of uth? the pads are expensive.. then there is thermal tape.. and thermal tape looking stuff..

also think im going to go with a controler from spyder robotics... and making it out of 1/2inch thick cell plexi.. vids on youtube oh how to make them even water tight for aquariums.. VERY simple to do and looks fantastic