I just got my first snake last night, obviously a BP.

55 gallon thick glassed aqaurium
Snake is 3 ft long

The previous owner only used a UTH on one side and said it has worked great for over a year with just that.

The problem I find is I keep my apartment pretty cool...68-72F during the day and 60-68F at night.

Last night I did some temp testing and used a probe thermometer put half way between the substrate over the UTH and it got to a max of 72F throughout the night. After reading on here I will do another reading with the probe directly on the glass above the UTH to see how hot it is. But if I had to take a guess its still not going to be as hot as it needs to be. This aquarium glass is thick, thick glass.

I know where the temps should be and that the temps he was at is way too low so I'm going to fix that today, but I'm wondering about what part of the tank to test the temps at.

Obviously I want to test the glass temp on the cool side and the glass temp on the warm side, how about the top substrate temp on both side? How about a thermometer in the middle of the tank near the top to get an idea of the general ambient temp? If I use a ceramic light I assume I need a temp reading on top of the substrate directly under the lamp?