White fuzz on fish

Question
I have a pretty big golsfish and it has a large patch of white fuzz growing on it's tail. It is about the size of a quater. The fish is just hangs on the bottom of the tank.

Answer
Kerri,                                                       Go to the pet shop and get erythromycin and treat your tank for fungus. Treat it for 7 days without your carbon. After 25% water change and new carbon so you don't reintroduce it to the tank. You can give him a frozen pea pinched between your fingers once a week. That will deter swim bladder infection. You can also pick up a veggie clip from your pet shop while your there and give him a slice of orange a couple times a week. Take the rind of of half. He will love you for it. Great for vitamin c. Stops vitamin deficiencies in his bones. Good Luck,Tina