Disclaimer:
I know people are quick to comment and say that it is cruel to put multiple of these fish together in the same tank. In the rest of that breath though, they would, hypocritically, curse me and condemn me to hell (which is ironically pretty cruel in and of itself).
If what I described above is an accurate description of yourself, then piss off.
Anyway, we have two tanks set up next to each other. One is a 20 gallon (which I got new from the store) and one is a 10 gallon (which I got from a work friend). We had one nice blue betta in the big tank. Since we had the second tank, we figured we could get a second betta. They are really great fish!
Bad news though. The filter on the 10 gallon tank just seemed to die a week back. We tried taking it apart to see if we could fix it, but no dice.
The water in the tank started getting really nasty, so we moved all the fish from the 10 gallon to the 20 gallon, except the blue betta -- since we were scared to mix the two males. We love these fish and don't want them to hurt each other.
After doing a partial water change on both the tanks this past weekend, I decided to try an experiment. Since we'd be home for the whole evening, we could keep an eye on the fish to make sure they don't hurt each other.
I put the blue betta in the tank with the other fishes -- right now, there must be about 40+ fishes in there -- dozens of Mollies, 2 Cory catfish, 1 Pleco, and the 2 Bettas.
The bettas have not fought with each other at all. I guess they're so used to the other fish that their aggressiveness has vanished. Both are really complacent.
The blue one just sits in the corner all day. While he was in the 10 gallon tank, he would position himself against the filter so he wouldn't be moved by the water flow. He's just really lazy.
The red one is more inquisitive, and is constantly swimming around checking stuff out.
They swim by each other all the time -- never have we seen them flare up!
The other fish are more aggressive, than these guys -- that's for damned sure. One of the white mollies has a gash in his check. One of the black female mollies had some kind of white scar on the top of her head. I've seen a few of the small mollies tailing the bettas and sucking / nipping at them!
Here are some pics of them!
And yes, I'll take better pictures later. Just wanted to put this up to show that Bettas can be together without harming each other!