My betta, Rakki, is currently in a one-gallon fishbowl. The light on the lid of the bowl heats his water to about 74 or 75 degrees Fahrenheit during the day. Sometimes it even gets to 76 depending on how much heat the computers are putting off (he's in our office/computer room). Our house is kept at 74 degrees right now, so that means when we turn off his light at night, his water temperature falls to about 72. I don't like that his water temperature fluctuates so much, but I have not gotten a heater yet because it seems to be almost impossible to find a heater that is small enough.
So far I am finding two possibilities:
I know Hydor is supposed to be a good brand, but I read some reviews about this one working too well for a one-gallon bowl. My fiance and I are gone at work a good chunk of most days, so we can't be home to keep an eye on the heater, and we definitely don't want to come home to a cooked fish.
That leads to me to the second option, the Marina Betta heater. It's supposed to heat up to 1.5 gallons, while the Hydor heats up to five gallons, which makes me think it might be safer for Rakki.
I know the obvious idea is to get him a bigger tank. This is in the works. Until then, I want to find a way to heat his bowl safely. Plus, I plan to keep the bowl as a hospital tank if he ever needs it, so I still need a safe way to heat it.