Join Date: Aug 2006
Location: Lupin Information Super Highway/Goldfish Information Super Highway
Bettas can be kept with anything placid enough to coexist with them except guppies and fin nippers.
Renowned fin nippers:
tiger barbs, black widow, Buenos Aires tetras, serpae tetras, etc.
The reason why guppies can't be mixed is that their colors and fancy tails offset the bettas and the bettas will assume them as one of their rivals.