How To Heat 2 Gallons

[aaronus]

I have a 2 gallon tank, and I'm looking for a reliable way to heat it so I can keep a betta there. The tank sits near a mail slot that lets cold air creep in, and it has no heater. So during the day the incandescent light heats the water, and at night it becomes uncomfortably cold. I can use a florescent bulb instead of incandescent to eliminate that heat source so it won't fluctuate as much.

I know I could move the tank elsewhere, but this is by far the preferred location in the house.

 

[Tolak]

I've used 25w VisiTherm Steaths in 2.5 gallon tanks with no problem.

 

[hellohefalump]

I'm using this on my 2gal
or you could sit it on top of a heat mat, like a reptile tank.

 

[aaronus]

Thank you guys. I purchased the item hellohefalump uses, and it is working well.