sometimes you can have perfect tank perameters but the fish may get stressed out by someone else picking on him or something, resulting in the fish being more prone to parasites or fungus. this has happened to me a few times when one fish decided to try and rule the roost. I've found that mela fix and pima fix can work wonders on those kinds of things. When used in conjunction they pack a better punch and a fish that you may have thought would have an early meeting with the porcelin god may come back with flying colors... Let me know how he does... Silver dollars are amazing looking when healthy and happy.
