You can also get Nori at a Asian market. Just make sure you get the one with no addatives, just dried/roasted Nori. It's made for rolling Shusi. It usually has a few different types of Nori made into sheets. Plus it's a lot cheapier. You can soak it in selcon or garlic if you like. There are also frozen brine that have been fortified with vitimans.
One thing I've noticed over the years and recently had confirmed by a local university is that Ich will come about due to stress. If the fish is healthy and in a happy enviroment, he can kick the ich in his own natural way. I've only had ich show up once in my tank in the last 7 years. And then only one fish got it, the others were fine. The curator at the university said he has never had it in any of their tanks. And they use a flow thru system using NSW. Nothing added to it so that they can return it to the ocean.
Just 2 days ago, I got a clown with ich from a friend. After just one day in my reef, most of the ich is gone and none of my other fish have gotten it.
Feed him well with a good balanced diet and try to keep him from stressing out. The change in color on him is a sign of stress as well.
Good luck with him.
