I use a dimming thermostat. I have better luck using halogen flood lights than the reptile bulbs which give off a hum when dimmed (in my experience anyway). I have the probe set on the basking surface just to the side of the hottest spot and keep it set at 105. The bulb is at a height which keeps it at around 80-100% most of the time. You don't want it to dim too much that it doesn't give off a lot of bright light. I have a heat projector set up on the other side for overnight too. That kicks in when the temp goes below 70 and turns off again at 73.