"FishNut" wrote:
I have a 150 watt heater, a 75 watt heater and a 50 watt heater. My
lighting consists of 4 T8 bulbs 32 watts each and 1 small 18 watt reptile
light. All I can think is that one of my heaters is shorting out and
causing all this extra electricity use. It doesn't make sense.

OK, let's work back. $65 of electricity at $0.075 per KWh (you don't give your
cost per KWh, so I'll just go with the national average) is roughly 1200W
continuous draw (that's 24 hours per day, 30 days per month, all the time).
Shoot, that's 10A -- a large proportion of a "normal" 15A circuit. If any one
of your heaters was drawing anywhere near that on a continuous basis, you'd have
boiled fish in short order.

Unless you have sky-high electricity rates, there's *gotta* be something else
causing this besides the tank stuff.