Not sure who to believe

Ok I just got a ReptiTherm UTH for the 55gal tank I have for Hera. But after reading the instructions I am confused. I have seen people mention that placing the water dish over the UTH can help increase humidity, but the instructions say NOT to do that since if any water comes in contact with the glass then it can cause stress cracks.

Is that true? I have a good inch or so of cypress bedding down to help insulate against the heat so she doesn't get burned so I think that is ok. And one last thing, I can't remember which is better: a Rheostat or a Thermostat and what was the difference?

You can place the water bowl over the UTH, as long as your not putting ice cold water in it, and letting it spill over. Plus...your using an inch of substrate. I wouldn't worry about it.

Thermostat: It regulates the temperature at the level you have it set at. If you have it set at 92'F... it will keep the UTH at that temperature, even if the room temperature rises or falls. They are a lot better than a rheostat, but more pricey.

Rheostat: also known as a dimmer. It just controls the voltage/amps/or whatever going to the UTH. Think of it as a volume knob 1 to 10. That's all it does. If you adjust your Rheostat to have the UTH sitting at 92'F when the room is 73'F. That's fine.....but if the temperature changes in the room up or down. The rheostat WILL NOT compensate for it.

I have my BP's water dish over her UTH to increase the humidty. She also has aspen shavings as her substrate. So far, I've had no problems with it.

A rheostat is like a dimmer switch. The more you turn it up, the more power goes through the appliance, and vice versa. It is good for manually regulating the temperature, but it still fluctuates a lot. A thermostat will automatically regulate the temperature. You program it to only hit a certain temp, and it will stay at that temp. If the temp of the room fluctuates or whatever, the thermostat will automatically adjust the temp to be at the one you programmed it to be at.

Ok that was what I thought the difference was. Thanks guys!

There's no need of putting a UTH under a water bowl for extra humidity... you can simply do a screen top made of aluminum foil & duct tape... you can find it in the DIY forum... & yes it does cause stress cracks. Hope this helps.