Well you made a great decision by coming here, this is a wonderful forum full of great people. And it sounds like you have a wonderful start already on the setup.
You are right about the thermostat probe placement. I stuck the uth to the tank with the probe between the glass near the center of the pad. The reason you don't put it in the tank is because if the snake moves the probe to a cooler position it will make the uth get too hot. The one you have will get around 115+º F if it is plugged straight in and probably warmer if it is under a tank so I wouldn't suggest using it without a thermostat. Remember you probably will not feel warm from 90º surface temperature because it is near your body temp. You will want to test the surface inside the tank with an infrared thermometer to be sure, and don't forget if your snake burrows into the substrate it may be warmer at the glass. Adjust your thermostat accordingly. As for the ambient temp, don't try to raise it with an uth unless you stick it on the side. Cover most of the top to keep in heat/humidity leaving only a slightly larger hole for your ceramic emitter. I cut the lid from an old tub for mine, leaving an inch around so it doesn't melt.
And post some pics if you can. We like pics.![]()