Its Autumn here is Aus, 5 of my tanks are un-heated but the bettas are healthy and active, eating well and playful. But winter here got to about 12-20 degrees Celsius, pretty nippy for the little critters. So hmmm, I need some heaters don;t I? Man the betta heaters in the pet stores are about $10, thats $50! D: Dilemma Dilemma! But, In my spare time, on cold days I get heater packs in towels wrap them around the tanks & single 4 gallon bowl they are warm enough at a nice 26-27 Degrees celsius. I also get warm water and add about 1/4 of a litre of warm water to there tanks. All seem fine but none have done a winter unheated. Hmmm, they are tough little guys, and girl. Well at least I can use the spwn tank heater for Senjii, He has the biggest tank.