Chronic Ich

Try a garlic supplement in his food. The LFS store should sell it. I use Kent's garlic supplement and put 1 drop on a cube of frozen after it thaws and then mix it into the food. You can do this daily as it doesn't hurt the fish. I have never had any parasites on any of my fish using this including several tangs and clowns.

Mike

There is often a temptation to ignore this, thinking the others will not be attacked. However in the small confines of an aquarium time can make a huge difference with marine ich. Usually it subsides for a while only to return with a vengeance worse than before; the trophonts/protomonts grow in a cycle, dropping into the substrate and then re-emerging in higher numbers. This cycle confuses a lot of hobbyists, eventually your fish get eaten alive, and believe me, left unchecked marine cryptocaryon a.k.a. ich will kill every one of them.
The FW dip was a good idea (providing you checked temp/pH) but that will do nothing to kill the hundreds of parasites lurking in your substrate. If you have live rock or other invertebrates the copper will kill the inverts, so you need to move ALL the fish to a quarantine system and treat them there for 30 days. (and it's not impossible to trap the fish in a clear container or bag if you bait it with food, many have done this). Lowering the specific gravity (salinity) in QT to 1.018 will help. This is the preferred method; While you are doing this, the trophonts in the display tank will starve. You can leave hermits, shrimp, stars etc. in the display, but you need a biofilter in the q-tank during treatment and monitor daily for ammonia.
Also, be advised some species (I. e. eels, puffers, moorish idols, etc.) are harmed by copper treatments so research your charges.

Turn up the temp to 80 too. This can help shorten the life cycle of the parasites as well as bring them under control in a minimal amount of time.

Your UV will help a little on the parasites but make sure you have the flow moving >60 gal/min.

Thanks for the reply back. The garlic theory "has worked" for me but I'm not sure that is a science. However, so far everyone I have talked to seems to do much better after feeding garlic in their food. I still have yet to ever have ich in my tank. Knock on wood....