Ok, great that it fell off. Does his regular diet have any veg matter in it? Very important for omnivorous cichlids. If he wont eat any raw veg, and I understand that he wont eat anything at the moment, but a spirulina based pellet is a good addition to the diet. Or you can get spirulina powder from a health food store and sprinkle on damp food like raw shrimp or tilapia. I also totally concur with keeping the water pristine. Should you end up having to treat and are pressed for room spare tank wise, a big Rubbermaid tote will suffice. An hob fits nicely on them. It never hurts to start with an epsom salt treatment, 3-4 days. Beyond that API General Cure is a decent broad spectrum med, but tough call when you cant pinpoint the exact ailment.