having had lots of tanks in the past i favor salt over everything. i would never put chemicals in my tanks when salt can cure just about everything. it is great for fish that are flashing (i think they call that ich now) or white spot or fin rot etc. for heavily infected fish use a salt bath in a container or for lesser infected or just a general precaution salt the whole tank. a fish keeping book from 50 or 60 years ago will tell you the quantity of salt to use. obviously, if your fish has dropsy you will not save it, dispose of it and best to salt the tank. in my mind, chemicals are a waste of money. also sea salt is a wast of money, table salt is as good as or better.