Thermostat or Rheostat?

Hello all! First time poster, soon to be first time snake owner. I'll be buying the supplies and such next week, my snake the week after that. However, I'm having a little trouble with something. I'm going to use an undertank heater, but I've read from many sources that I should use something to control the UTH so that it doesn't get too hot and possibly burn my snake. I've looked up both the thermostat and the rheostat, and know what they do, but I can't decide which would be better to use. I would appreciate any help y'all could give me. :idea:

I prefer thermostat because it regulates the temperature to the outside air. If it's cool out, the thermostat will turn on the heat and when it's hot it turns it off. A Rheostat just provides power only and the room could be 100 degrees and the heat will still be on the pad.

Like Meg said. With a Rheo - YOU are the thermostat. If your room temps are fairly constant, and you're there to tweak it up or down as needed, and you're okay with constantly fiddling with it, then that's a good option to use. But if you'd rather monitor the work of an electronic thermostat (like me!) then the thermostat is worth the extra cost.

That's what I was thinking, but I was a little worried about how well the thermostat could keep the temperature stable. If the UTH is turned off, and the temperature drops a little so that the thermostat turns it back on, would the UTH warm up fast enough to prevent the temperature from dropped too low?

You'll get about a 3 degree fluxuation with an on/off thermostat above or below the set temperature. Not enough for a corn to even care. I use good proportional thermostats on my arboreal snakes as they are more sensitive. They keep the temps within a 1/2 degree

That's not so bad then. Thanks for your help, everyone. =) I'll definitely get the thermostat instead.

you should also ask about the cost big differene in cost of the two

Not that big a difference. I bought a very good on/off thermostat from Big Apple for about $30 The rheostat I accidently ordered was about $20 something. I can plug 3 mats into the other one. Only one into the rheostat....better deal. If you're thinking about a proportional thermostat, that's different. You're looking at about $110 for a Spyder Herpstat...not really necessary for a cornsnake though. Here in S. Carolina, the temperature range quite a bit all season. They are quite tolerant of temperature. As long as it's in the vacinity.....it's good.

ReptileSupply has the Zoo Med ReptiTemp 500R for 20.99$ and the Zoo Med Rheostat is 13$ so not a huge difference.

I used to use and be happy with the ZooMed 500Rs until I put permanent probed max/min thermometers in the cages that had them and got to see the nearly 20F temperature swing, getting both too hot and too cold. The $40 Big Apple Herp BAH100 works well without nearly as much swing, and a Herpstat, while seemingly very expensive, will hold the temp within a degree of what you have set. The $110 model works fine, and the $135 model has high/low temp alarms (among many other fancy bells and whistles). BAH is releasing an improved modle of their basic thermostat December 6th. You might want to wait and see what that's all about.