Hey, I've been searching the forum to try to figure out what's wrong with my wife's fish without much luck. So I thought I would post about it and see if anyone has any ideas. Our silver tetra has been having trouble swimming for a couple months now, and getting worse. He started out with just a little list when he was floating, and has progressed to the point he now is just kind of bouncing up and down pointed straight at the top of the tank. It seems if he stops he sinks to the bottom of the tank. I uploaded a video of him tonight - below. The water tests fine, although we just use the test strips. There are 3 tetras, 1 sword tail, 2 Chinese algae eaters and a Pleco in a 30 gallon tank. I asked someone at Petco about it and showed them a video but they said they didn't know what it was and the fish was probably just dying and not to worry about it. Any help would be appreciated.
https/youtu.be/BbViLQ4SXjk
https/youtu.be/BbViLQ4SXjk