jm1212 said:a 1.5 gallon tank is to small for a betta. try a pair of male endlers instead and thats it.
It's a 2.5 gallon tank, not 1.5 gallons.
EmmaS, I have a filter that hooks onto the back of my tank, it's really quiet and you can adjust the flow (and takes up pretty much no space at all in the tank). I'm at work right now but when I get home I'll see what brand it is and I'll let you know.
I have yet to find a heater small enough for my 3 gallon tank... It's such a pain. Luckily I live in a hot place.