Hello everyone. I am very unexperienced when it comes to fish care. We have had our tank since February and we've had bad luck (due to ignorance, honestly). Well we've finally seem to have a good environment for the fish (2 platys, 2 Dalmatian mollies, 1 rainbow fish(lost one today), a plicostima(sp?) a yellow snail & a blue snail in a 25 gal tank. My question is, after researching I have realized that the rainbow fish we lost today was constipated & ended up with swim bladder(?). After reading about it & watching the fish's behavior I realized that I'm pretty sure we've lost a few of our fish from this. Obviously we need to change food. But what should we get? Currently we are giving what we got from pet smart. I think it nay be a store brand even. We were told that "any tropical fish flakes will be ok". This is obviously not the case! Any help would be greatly appreciated! Thanks!