Yeah I have isolated him in a 20 High unforetunetly. He still doesn't appear to have ick but i think that i will Copper-Safe the tank today.
AquaMan 2, i normally feed krill but i have tried everything from Frozen Trigger Formula to Live Goldfish to no avail.
Puff (er) daddy: (You may already Know all this but here goes anyway)
-Are you treating him with anything? I have had varied success with copper in the past, if i were you I would isolate the Grouper in a hospital tank with no substrate (because the ick can live there). However, I would add rocks to make him feel comfortable (And you can take them out and wash them if needed). In my opinion, your best bet is to try hyposalinity, slowly over several days reduce the saltinity to no lower than 1.019. Then, gradually bring it back up to your normal level. In addition to this, i would look into freshwater dips or even formalin dips. Personally, i think that a formalin dip is easier on the fish and i have treated several Tangs for ick and other parasites using this method and have had a lot of luck. For the exact procedure you might try doing a search in the disease and treatment section.
Hope this helps