I've never really thought after having a fish for several months and then them dying is the store's fault. It's just that I've bought some sword tails,tetras fish like that from 'actual fish stores' and then bought some from Wal~Mart and the ones from wal mart just don't live as long. I think it's because their immune systems just aren't as strong as other fish other people own/raise.... Some are just tossed here and there and aren't looked after and cared for as good as others... It could be like down the line or something and a fish be ok for a while but then die not long after you get them because of several reasons---not necessarily being your fault or the stores...