flexwatt and 20 gallon tank

Sorry to rehash something everyone has probably answered a million times, but I did a search, I promise! I searched on flexwatt and aquarium enclosures but came across a post that said flexwatt may crack the glass if used without a thermostat. :eek: Is that a proportional thermostat or any thermostat? I am planning on putting an 11" flexwatt under the tank wired to a Ranco thermostat. Is that going to be a problem?

Also, the probe goes right against the flexwatt, I'm reading. It just doesn't sound right to me- wouldn't you want the probe on the floor of the enclosure where the snake will be? Can someone explain?

Thank you yet again!

if it is run full power and gets to a high enough temp, it can crack the glass. Keep it on a thermostat and you are fine. Just be sure to attach the probe to the glass on the inside.

Also, if you are using fw on the bottom, be sure that you aren't using a thick substrate like mulch or aspen...that will basically serve as an insulator and the fw will do nothing for your ambient temperatures.

Thanks! I'm planning on using newspaper to start off.