ahhh.. heck.. its better to put it in a 1 gallon tank so it wont be stressed. Betta should be in a solitary cinfinedment. buy 2 male bettas and 1 female betta. what to do with them? here..
1. put each betta in a 1 gallon jar. put the jars beside each other.
2. The bettas should not see each other since they get stress in flaring at each other, so put a card board just enough for the bettas not to see each other.
3. the female betta can be put anywhere just dont put it with the males, for me put it in your community tank, just be sure you can catch the female y? tell you later.
4. once a week water change the jars of the betta.
5. 3 times a week let the bettas flare at each other for 5 min so they can give of the fats in their body.
6. once a week each male betta should chase a female in a small container for like 2 to 4 min so male can stimulate mating since they have no sex drive.
7. check every day if their are bubles in the jar so you can know they are healthy and happy.(they do not need oxygen, they breath atmospheric air)
8. if you do this steps you will have a very nice happy betta
and life span will be long to. enjoy