Like Tim, I don't want to keep the ambient temps from touching the thermostat probe as much as possible. I also don't trust having the probe in the actual tub with the snake for fear of them moving it or getting caught in any adhesive that might be used to keep the probe taped down. In each of my racks, I have an empty tub with just the thermostat probe in there. I have tried just having the probe taped to the heat tape outside of the tub, but it seems as the ambient temps fluctuate so does the thermostat temps. If the ambient temps cool, the probe feels it and increases the temp of the heat tape.

Of course, I don't have many snakes yet so I have room to do this.