My house is old, not well insulated, and we have an electric furnace. All this adds up to a large heat bill in the winter. We tend to keep our heat down at 55-58 when no one is at home and during the night, during the day when everyone is home it stays at about 60-62. My bp's are in 2 20 gallon aquariums for the time being. I plan on building a rack when I have more snakes but I don't have the time, money, or enough snakes for the time being. Anyway, I have an under-tank heater for each bp and keep a 100-watt light on for heat on each aquarium. I feel like this just doesn't provide enough heat for my snakes as the room still stays pretty cold. What would be the best way to keep the room or the tanks warm without me having to jack up the heat in my old un-insulated house and having a crazy power bill?