My fish, Fievel, just recently started swimming weirdly and acting just kind of crazy. He darts around the tank suddenly and he'll do nose dives into the rocks just out of nowhere. I've had him for two weeks now and as of a few days ago he was doing great...eating like a pig and no weird behavior. I did have him in aq salt for the first week because he had fin rot....that's gone now so I stopped the salt a couple days before he started acting weird.
His tank is 2.5 gallons, heated, filtered, and I do water changes twice a week. Anyone have any idea what it could be? He appears to be perfectly healthy except he swims crazy and now he is hiding a lot and won't come up to the surface to eat.