I have a sailfin along with a blue tang, coral beauty, foxface, pink skunk, yellow gobies, green chromis, sixline wrasse, and sleeper goby, in a quaratine tank treating with hyposalinity. All the spots on the blue tang have disappeared, but the spots on the sailfin never have changed. They have been on the body of the sailfin for about 2 weeks. Do you think this is ich or velvet. Thankyou for your help....Mike