I don't think Bettas bite their fins due to tank size, I think it's generally because they find their fins too annoying, since they're carry such heavy finnage it's a drag to swim around with it and they get tired easily. So biting off a few chunks will ease the weight. If you provide surfaces where your Betta can rest on, like those Betta Hammocks, it'll be easier for him since he doesn't need to swim that far to reach the surface to breathe. Also if the current is too strong, they might bite off their tails so they can swim easier.
I wish we all knew a conclusive reason(s) for why Bettas bite their tale and how to tell. Hahaha. It took me forever to try to find a solution and the only thing that seems to be working is a consistent light schedule/ritual I do.
And Micho, he has plenty of those and even hangs out in some of the roots of the floating plants (granted, now that I think about that, he bit his fins before I got the taller plants and floating plant so you might have something there).
Either way, I'll just leave it up to my gut, then. I'll buy a fish when my gut says "YOU WON'T CARE IF HE NIPS HIS FINS A LITTLE, GET HIM!" Hahaha.
And thanks, Sakura, I'm glad that not everyone has the same experience.
I think so and because they can see the other betta and he's really close. It must get them so excited they mistake their big trailing tails for another male. Or they just are stressed. I'll never know but sadly, my two in a divided tank have to stay that way - no room for any other setup right now.
Yeah, I'm coming under threat of having to get divided tanks. I started to realize I wanted 4 Bettas and the least I'd be comfortable putting them into is 5 gallon tanks. I have 1 5 gal and 1 10 gal. I originally want to keep 2, but then wanted 3, and now that I realize my likes and dislikes in terms of betta fish, I'm trying to fight off my want for 4. I only have two (one of them is going to be given up since he was just a rescue), but my current fascination with Aquabid and my love to going to my local stores is making me realize how hard it'll be to do that.