Do I have to have a temperature gun or can I just lay my accurite with probe. In other words, if I lay the probe directly on the substrate directly above the flexwat is that good enough or do I need to use the temp gun to measure the substrate temp? The room is 75 and I've had to crank the flexwatt up to 100 to get 85F, is that normal and should I go a head and crank it up some more since the hot spot is recommended to be 90F?