Three Stripe Damsel Rotting?

[NewSaltyReefer]

The tank i take care of were I work has had this damsel fish in it for about 8 years (plus 3 other fish). Last week he developed a "rash" on his side. At first I thought he had just scrapped himself, but now his scales are starting to come off and you can see his flesh.

It is a really large spot that now covers almost 3/4 of his side. Does anyone know what this could be?

About the tank:
I took over taking care of the tank which had been neglected for sometime. It had a major buffering issue which is now under control (pH would swing drastically). Now I am working on getting the phosphates down, which were so high that after two 15% water changes my kit can finally gives me a reading of about 3.0 (API PO4 kit).

All other params are normal!

The only chemical i have added is Pure Phosphate remover (the brown ferric oxide stuff).

Any suggestions or comments? Thanks

 

[Percula9]

The best thing to do is treat the fish with antibiotics in a quarantine tank for 7-10 days. You probably let it go to far and the fish might not survive. Whenever you see any type of body sore or ulceration, it must be treated immediately. The wait and see method doesn't work. It usually results in dead fish. Keep working to get the phosphates down. Don't use pellet or flake foods. These make your phosphate levels up. Use frozen foods.

 

[black_majik]

Yeah, get that fish out of the main tank and treat with Melafix and Pimafix would be your best option.