You might also want to set your desired temp at the bottom of the tub, not on top of the aspen. Snakes can burrow and you risk burnsbecause to get 92-94 on top of the aspen you are going to have to set the stat pretty high. That could mean 110 on the bottom of the tub. Of course, the less Aspen you use, the lower you will need the temp on the floor of the tub to be to get the temp you want on the surface of the Aspen