Let me explain a little about my basement tanks. I wrap my
tanks with fiberglass insulation to keep in the heat. I have
three 45-gallon plastic tanks that are heated from underneath,
each by a heavy rubber foot warmer measuring 24 inches by 48
inches. They only use around 60 watts of power, which is reliably
sufficient. Each one has a thermostat for maintaining the water
at a constant 80 F. degrees. I also keep submersible heaters
for standby in case the pad heaters fail. I have had two of the
pad heaters for ten years.
The warming pads had never failed until one of the thermostats
did in December 2005. I had gone away for a few days and upon
returning I discovered that the thermostat had stuck in the full
hot position. The water temperature was well over 100 F., 107
F. to be exact. All the pads had been cooked and I thought that
I had lost them all.
But lo and behold, a month later each pot had a little tuber
the size of a kidney bean and they are all sprouting again. This
demonstrates Mother Nature at her best -- allowing me to accidentally
force my tropicals to tuber!