wood base, the thicker the better, 1/2 inch urethane insulation with foil backing, floor protectors that go on chairs to form a space between the insulation and the bottom of the enclosure so as not to smash the self regulating heat tape that goes between them. Inside the enclosure, the substrate I use is aged cypress mulch mixed with aged leaf mulch, the older the better. at least a year for the cypress and 3 years for the leaves.It is a few inches deep because I use a hot rock buried beneath one of the hides and don't want the hide and rock to touch, or the tortoise to be able to get to the rock.For the third heat source I use golden rods which max out at around 120 degrees for the 8 watt size, the larger the rod the max temp goes up some but never hot enough to burn. For the tops I use the store bought aquarium tops with the fluorescent fixture and remove the protective glass from below the bulb to allow for uv rays penetration. A couple of important things are to seal all electrical joints with liquid electrical tape,and this system works best without thermostats if the setup is in a temp controlled room, I have mine in 75 degree rooms which works to keep the enclosure at 85 degrees,Everything I use for heat is self regulating so once I get it set it stays the same.
