Temperature

Quick question: Where is the best place to measure the heat for the warm side of the tank?

The best place to measure simply for information would be on the bare glass of the tank over the heat mat, but if you're talking for a thermostat probe then it would be best directly on the heat mat, outside the tank.

Okay, i put the probe on the bottom of the tub. We're using a 23 foot heat wire mounted on the outside of the tub in a coil along the bottom. We had a spare dog crate door thats folded in half and elevates the tub about a quarter of an inch off a tile floor to keep it from over heating. So, should I put my thermometer on the bare tub and measure the temp or on top of the substrate. It's a circle gage thermometer so it seems to heat up quite a bit under it and I don't think the temp reading is accurate. Also, what do most of you keep the humidity at in your tubs?