I use the green heat mats from big apple Herp because they don't have to stick to anything. Because I have two enclosures and wanted to save some money I got one slightly larger one and placed it halfway under both tanks (5.5) and have the thermostat probe wedged between the two tanks directly on the pad and set so the pad won't get dangerously hot. I then went around with my infrared thermometer and dialed in the temps I wanted based on how hot I let the pad get.