Originally Posted by nicetry
This is a poor choice for a captive fish. Very few survive long (more than a couple years) in home aquaria. It will certainly outgrow a 55. They are very diet specific and require large amounts of sponge in their feeding regimen. They also eat algae based foods. Fading can be associated with dietary deficiencies or even stress, to name a couple. How long have you had the fish? What are you feeding? Can you post your actual parameters? Other tank mates?
I kept one for two years back in the day. Ate everything, survived a substrate change, etc.. Found it dead on the sand one day.
Exactly.
Also, jacha66, if your fish is less than 2" long, what you're seeing perhaps is a change of coloration from the juvenile to the adult stage. The blue spot will change to entirely black, and the spot will grow and take up more than half of the coloration from the pectoral fins to the tail. The dorsal and anal fins will wind up being trimmed in red and blue, and the mouth will turn black. They are a beautiful angelfish, but not for the inexperienced aquarist. They often lack the nutritiion that they need to survive in captivity. If you can meet their dietary needs, then these fish have the potential to grow to 18" long as adults, so you'll need to upgrade your aquarium to a minimum of 200 gallons IMHO.