disease question

[jja]

I have had a very successful reef tank for 2+ years now and just changed tanks. I went from a 55 to a 90 show which is very tall and narrow but I also changed from a wet/dry to an established fuge. This is new to me and all of a sudden I seem to have the beginings of what looks like ich. I have never had ANY problems with these same fish in the whole time I have had my tank. I know it could be the stress of the move, but what causes ich? My water params are all perfect. Is it just from stress? It has only been set up in the new tank for 2 weeks now. One other thing is I added an arrow crab that I am now going to try to catch after reading some posts on them here. Could it be stressing them out? My shrimp seem to hide a lot now.

 

[beth]

The fish or some fish in your tank came in with the ich but, fortunately, was kept under control or in check due to the health of your fish....this is rare but does happen. Now, the fish have some ich from time to time that went unnoticed. When you made the move, the fish got stressed, and that was that.
Ich is a fish parasite. It feeds on fish, but it is not always on the fish. It has a 3-stage life cycle which includes: on fish, in water, and on substrate. Thus, you see how once it is introduced to your display, you have a total system problem.
I suggest that you QT your fish and treat with hyposalinity. Leave your display wo fish for the duration of the fish treatment. This will resolve the problem of ich in your tank as ich cannot live without fish.