What could have happened to our fish?
my father purchased a few fish yesterday. we took them home and put them in the tank doing the same routine we use when we get new fish. we put the fish into the tank but still in the bag they came in. we then wait a few minutes (15-20 usually) before releasing them. once they were out they started acting funny. crashing into other fish and swimming sideways. within an hour 3 fish died out of the 4 we bought. the water temperature of the water in the bag and of the tank wasn't very different and none of the other fish were acting like this. could they have died from shock? PS all the fish were tropical and fresh water fish. if that was important info to know.