If a store keeps getting in sick bettas, then they need to change their supplier.
If their bettas get sick while they are in the store due to neglect and bad water, then the store needs better employees.
Bettas are one of the hardiest kinds of fish out there. No store that is worth a dang would have sick bettas in such high numbers that they'd need someone to foster the sick ones. If they do, then they are a terrible store and/or have a terrible supplier. I spent two years taking care of the fishtanks for a pet store (Pet Supplies Plus in Alabama) and I really never had sick bettas at my store while I was working there. (More delicate species of fish, sure, on occasion, but not bettas.) I attribute that to a combination of having had a decent supplier and taking good care of them while they were at my store.
If any store in my area consistently had sick bettas, I'd want to know why. If you want to spend your time fostering sick bettas, it's your business, but the problem is, you'd be doing the work of the employees for no pay. I wouldn't do it, personally. I might save an individual betta or two (or three), but I wouldn't give them back to the store afterward so that they could be possibly neglected again. (Or sold to some clueless person who immediately kills it because they don't know about chlorine in tap water.)
Sorry for the mini rant. I'm tired and crabby right now. LOL. It WOULD be worthwhile to attempt to teach their employees how to take better care of the fish, though, if the manager would allow that.
I'm glad there are kind-hearted people like you, though, who care enough to try to help animals. *Hugs*
Last edited by SnowSong; 04-22-2013 at 12:18 AM.