How many watts of heater do I need?

I have done something like this before. I used 1" foam board to insulate the tank, piping insulation around the pipes, even to the point of a replaceable 4' foam piece on the front of the tank. Also, remember (or look up) the very recent discussions about heaters? We discussed the logical reasons for using multiple small heaters and how manufacturers mislead us into buying heaters that are twice as powerful as needed. We also talked about the advantages of cooler temperatures.

Edited by Mark Peterson - December 13 2014 at 6:54am

An insulated system won't lose heat in the garage much faster than a tank in the house. Start with ~1 watt per gallon; 2x50 watt heaters and realize that a heater that remains ON longer is not a problem. In fact, I believe it's the number of times a heater turns on and off that shortens its life. As in everything, go slow, be patient and add more as needed. That's my philosophy.