trouble

I am simply having a devil of a time taking care of the behemoth fishes these days. Tres somehow managed to injure himself over the weekend; apparently in the wee hours of the night. At feeding time Sunday morning, I noticed he was lying in a corner on the bottom and didn't immediately swim up for food (always a bad sign). He has a cut on his lip, and has mostly been lying on his side since, occasionally getting up and swimming around normally, but with struggle.

He has often exhibited signs of what I can only associate with epileptic seizures, if those are possible in a fish-- wherein one moment he is swimming along, quite in control, and the next he is overcome by a twitching and shaking, often leading him to collide with the sides or bottom of the tank. My assumption, as he shows no outward signs of illness, is that he must've had a bad one, and has got himself very bruised up as a result. I added a tonic for wounds to their tank water, but I think there may be nothing else I can do but allow him to rest. Nothing else I can think of. Pi is perfectly healthy (if a little freaked out), so it's definitely not the water.

I am feeling discouraged. Between my summer-long fight with cloudy water, and now this, I really don't know what to do.