My dogface puffer has ich. He is living with a picasso trigger and maroon clown. The other fishes don't appear to have the disease yet. This will be my first time attempting to cure marine ich. I've read up on different methods and I think I'm going to go with hyposalinity. My problem is not knowing whether to treat the main tank or using a hospital tank. I have live rock, live sand and hermit crabs and nassarius snails. Should I treat the main tank with all three fishes in it and move the hermit crabs and snails to a separate tank or move just the sick puffer to a hospital and treating him separately? I know crabs and snails don't like hyposalinity. Thanks!