Join Date: Apr 2014
Location: Southern California
You need to get a heater for sure. The Aqueon mini bowl heater or zoo med bowl heaters work great for 3gallon bowls. (I have 2 Three-gallon bowls and 1 one-gallon bowl, all with heaters). I wouldn't put any other fish in ANY tank that is less than 10 gallons with a Betta. There simply isn't enough room for it. Just stock your 3gallon really nicely with plants and hiding holes and he'll be very happy :)
I recommend mystery or nerite snails. You could also do a ghost shrimp if you have a covering for your bowls (as they do/can climb out).