I bought four minnows. they looked healthy in the tank, there were very few dead in a tank of at least 50. one had a broken spine and died shortly after I got home. the lady handled them roughly so I think the injury was from that. another one was hyperventilating and floating at the top. I expected that one to die. the other two seemed just fine, they were swimming around and even looking for and nibbling on a pond fish pellet. I cleaned the container thoroughly, it had nothing in it but water from their bag and about a third of it room temp from the tap. the same water my snails do just fine in. I was getting them used to the water in that. I left the room for barely a half hour. came back in and all of them were dead. not three hours after I brought them home. and the container was new, it was one of those plastic ones you keep them in for temporary/travel. is there anything I could have done differently? could it have been stress or injury?