Learn the "do's" and "dont's" About stocking bettas with other tropcial community fish.
Betta Tip #3
Remember to stimulate your betta everyday. By allowing the bettas to see itself in the mirror for about 5 minutes aday will be good for both your betta's mental and physical state.
Read First
Remember that every betta is different, so some are more mild and others are more aggressive, Remember this when stocking you betta tank. The best way to find out is by trying. I have seen some male bettas eat a whole guppy and others who will live fine with mal guppies. Another factor to consider is filter capability and tank size. You never want to overstock a fish tank or betta tank.
The Right Tankmates
Most bottom fish-cory catfish, otto catfish etc... Nothing that can eat the betta.
Tetras- most tetras will do fine, Again it depends on your bettas personality.
livebearers- Again depends on your betta, But some will tolerate guppies, andlarger livebearers such as mollies and swordtails.
Labyrinth- depends on your betta, but gouramies and generally safe. other betta species might not be lucky.
The Wrong Tankmates
Barbs- Most barbs are fin nippers which will cause your betta problems. Certainly tiger barbs jump to the top of the list. I have experiented with rosy barbs. They seem to work.
Oddballs- Never a good choice with bettas and small community tanks.