i had three fish for a couple of months. recently this week one of them started jumping out of the water (sometimes it would bang its head on the wall and twitch at the bottom of the tank), swimming into walls and rocks. i went to get the water tested, the pet store said that it was fine. now a second one died with the same symptoms. and i have a third one that'll probably die by the end of the day. does anybody know what might of went wrong?
