I had a black molly that had stringy white feces. I removed him and put him into a 1 gallon tank. Since then I have been treating him for constipation. He has been in a tank with fairly heavily emsom salted water. I did not feed him for 3 days and then fed him only peas for 3 days. Since then he has been doing better. He is swimming and back to eating flake food. I really want to add him back to my tank as there is hardly any room for him to swim in the one gallon. I have one worry though. On his side he has a couple scales that are a silvery grayish color. I am afraid that there maybe some kind of fugus or something. I feel bad keeping him in the little tank but don't want to risk my other fish. Does any one have any advise? I will try and add pictures.