Your goldfish is growing fuzz on him is he dying?

You are killing your goldfish by neglect. Your fishes water must literally stink. It is putrid and needs replacing. The fish has fungus caused by Ammonia in the water, and that is eating away at its flesh. Please do a water change ASAP and medicate the water by adding 1 level teaspoon of sea salt per gallon of water. Then follow the rules below. 1 inch of fish needs at least 1 gallon of water. (A goldfish will be a 10 inch fish and so needs at least 10 gallons.). :- Every tank must have a permanently running 'cycled' filter. :- Every tank needs at least 50% of its water replaced every week.. If you do as I have suggested, you may save the fishes life. Once the fungus goes and the fish starts to get better, you can stopp adding salt to the replacement water,and the water will slowly become fresh water again. I can guarantee that failure to follow the above simple rules will always result in sick and dying fish.