Updated: Mar 30, 2020
I'm happy to say after several years in the trade, I have found the term "fighting fish" is rarely used for the beautiful Betta species of finned pets!!
We find that many Betta cohabitate quite well with community fish. While you CAN NOT house 2 males together, as they are very territorial against their own, there are many fish they will do quite well with. Sometimes they live cohesively with females, however our biggest obstacle is watching for fish that are attracted to and nippy of their fins/tails more so than their aggression toward others. We do however recommend to keep them with more muted colored fish without fancy fins/tails as well.
We do not house our Betta in small containers, we have them right in our system with the community fish. We HIGHLY recommend all Betta owners house their beauties in no less than a 5 gallon, heated, filtered aquarium for them to be their happiest and most active. You can go smaller if you desire, however Betta will still thrive best in heated, filtered water.
We have the ideal tank kits if you will not be putting them in a bigger community tank!