Shoot, he is not looking good today.
He's pale, and when he swam up for a breath I noticed he's got some tears in his anal fin and tail. And one of his ventral fins looks is short and bloody. And he's keeping his pectoral fins sucked against his body. So basically every fish symptom you can think of
He's still responsive and still eating (feeding him antibacterial pellets).
I went ahead and put another dose of Tetracycline in there, since that's what I've got, and I fear doing nothing.
I also added some coppersafe (haven't added any after the last couple water changes).