No, they won't. Bettas are usually compatible with peaceful schooling fish. They just can't be kept with other Bettas, with the exception that SOME females can be kept in sororities (5 or more females in a large tank).
Also, tetras really do need bigger tanks than 10 gallons for swimming purposes. Yes, they'll do fine in a 10, but they really come alive in bigger tanks (and with a lot of other tetras). They could also nip at bettas, I've seen it before. It's really a personal preference so you could get some.
Anything around 5 gallons, you're looking at shrimps and snails. Shrimp are perfectly fine for the bettas to eat. My girl seriously ate 3 in one night, and one of them was twice as big as her. -_- Needless to say, she didn't get fed for a little while. :P Oh well, they're just snacks for her now.
With 10 gallons you would have more options. You could divide into two or three sections and get other bettas. You could also get cories, which are cute little fish that usually stay towards the bottom of the tank, however my previous ones loved riding the current. Otos are another option but you would need live plants.
As with anything, making communities really depends on the betta's personality. My current girl, the beast that she is, would be way too aggresive in a community tank. Sometimes trial and error is necessary. :)
Last edited by SaylorKennedy; 03-21-2011 at 04:13 PM.
I have no idea really about that! lol I've heard so many different things. some claim 1 gallon is enough for a betta, some claim they can live even in a tiny container smaller than that. some say they should be in at least a 5 gallon tank. some say ten gallons. so idk what to think lol
It depends on the fish. Divide it, and then try it out for while BEFORE you get another fish. If the fish seems fine, get another one. If he seems more stressed or unhappy, let him have the tank to himself.