just a little update.. i removed the large hide checked the bottom of the tub (from inside) to see how the belly heat would be and it's barely anything?? i did have newspaper lining the bottom under the aspen chips in fear of the UTH getting to hot and burning him so i have removed that.. could it be the foil tape not letting the heat through?? that would be my guess why the tank temp is so low as well.. i have a thermostat hooked up to the UTH but i always thought u still had to foil tape it still??