So I had to conficate some goldfish from a family member who kept them in less than ideal conditions. (mainly really overfeeding them) So the water quality was lacking. While the fish all seem to be doing well now the Red Top Oranda had turned completely white a few months ago. I have treated the fish with salt and are going to give them a melafix dosage tommorrow after a water change. I cant find any difinitive answers online except that it may be fungus, lack of light, parasites or bad genes. He moves well now and eats plenty but when I got him he did alot of resting on the bottom. Any thoughts because I am going to give them a away to LFS and I dont want him or the others to be sick. Thanks for any help.

pimafix is better than melafix for fungus. Melafix is more for sores, infections, and damaged fins/scales.

That's really all the insight I can give you. I'm a goldfish noob, sorry.