note: Not my Photo, from Flickr with share permissions.
I joined back in 2013 but never made a post. Ahaha, so this will be my first but I want to see what some people's opinion on this matter as its quite divided. I been keeping bettas for close to 10 years and in the last 6 years of me keeping them, I have never kept a betta solitary. It has always been in a planted community tank and I honestly never had a betta so aggressive to the point where it was actually hurting or killing other fish. They adapt very quickly to their communities and find a position on the hierarchy for themselves, usually quite high up, if not the big boss.
Here is my 2 cents on it:
There is just nothing natural about a fish living its entire existence alone to me. Even in the wild, under what circumstances does a betta never encounter other life forms? It also makes no sense for a betta to be continuously aggressive towards fish that pose no threat to it, male bettas fight because by being territorial, they hold better opportunities for mates but there is absolutely no benefit in attacking fish that are just part of its habitat.
In a community setting with other fish, snails, shrimp and what not, I feel like they live far more fulfilling lives. They actually do stuff like forage for food, defend and establish their position in the community, sometimes hunt fish fry if available, fight for food, explore and interact with their tank mates. Betta housed alone I feel like are so under-stimulated, they just sit there and only do anything when their human comes to feed them.
While bettas are definitely territorial fish, I think the aggression trait has been blown out of proportion. Along with puddles, eating bamboo and other myths, I feel like a betta being too aggressive to have tank mates is also a myth. It is definitely true that there are fish just incompatible with bettas and the thai-bred fighters are probably uniquely too aggressive but I feel like in general, bettas are totally great additions to community tanks.
If you do believe bettas should be only ever housed alone, what are some of your reasons? What are some successes and failures you had?