The temperature has been dropping very low lately and I am finding it difficult to keep a consistent warm temperature on all of my fish. I have turned to bringing a portable heater into my room and setting it next to my fish, which has actually been working for the fish closest to the heater (tonight it is very cold, but he is at 76). I only have one heater, for my 5 gallon with one fish in it. The lowest I see them drop is about 68 at night, and that is for the ones not directly getting heat from the heater. Anyone know ofways to keep multiple fish tanks warm with the very cold midwest winter weather? I don't really have the money to buy 3 or 4 more heaters.