Being concerned for the welfare of my beasts. last winter I splurged
(against my husband's best wishes) and purchased a tank heater. It was a
fancy one that turns itself on when the temp goes below 40degrees. We
argued for so long that the first freeze came and went before it was ever
installed. Just to prove my point, I dropped an aquarium thermometer in
the water close to the bottom. Well, cold as guess what!?!
The water never got cold enough to turn the thing on, even when it had
several inches of ice on top.
Becky H