I stuck my hand in today to snip off a dead leaf and realized how cold the water is in my 10 gallon tank. My betta seems fine, but I'm sure he's not too happy with it. I have a thermometer in there, and I kept an eye on it the first month or more closely, but I guess I slacked off into the routine of assuming it was still ok. It's reading at 71 degrees right now. My living room gets fairly chilly in the winter from the front door getting opened 90 times a day. The only heaters sold at my lfs are the Deep Blue sticks, which are way too tall for the 10 gallon, I could put it horizontal I guess but it'd look pretty ugly. He currently has a Tetra heater from Walmart designed for 5-15 gallon tanks.. and I guess it's not strong enough. Can someone recommend a stronger one that won't take up half the wall of the tank?