maxwellag said:
I've thoth bout upgrading betta tanks but they seem to be just fine how they r. I have had one of them for almost 2 years now. My lfs says that they would even be ok in a half gallon, but I think that's cruel.
I have 2 female bettas in my 20g tank as the centerpiece fish, and they're probably the most active fish in my tank, swimming throughout all 20 gallons of it. Based on my own experience, I almost have to even question keeping a betta in anything smaller than a 10g tank.
I understand the plight of chain pet stores and LFS when selling male bettas. You can't exactly dedicate a single 5g tank to every male betta in the store; imagine the total number of tanks they'd need just to house them alone. Also, because of the randomness of male betta temperament, they can't trust spreading them out among the other populated tanks and putting other fish at risk.
However, that said, they shouldn't be suggesting that bettas, male or female, would be just fine in any of the small tanks they sell. Sure, they may be tolerant enough to sit in the butter-sized containers, breathing in their own waste and ammonia, but subsisting in those conditions isn't the same as thriving in a 10g+ tank with plenty of room to swim around.
IMO, the only things a 5g tank are good for are a shrimp-only tank or hospital tank. You could stretch the usefulness of a 5g into the role of QT, but only for small fish and not in mass quantities.