ICH but maybe not ICH

[wamp]

I have had 2 fish die recently (as some may know). A sailfin tang and a Clown tang. The white spots, I assumed Ich, Were present on the Clown tang when in bag from store. I added the fish (i know, i know) and they seemed to go away for a couple of days. After that they reapeared on the Clown Tang and the Sailfin. Now my question is. None of my other fish, 3 green chromis and a maroon clown, Showed any signs of illness or the spots. Could it be something other than ICH. I want to replace the Tangs with another one to graze on some algea I have in the tank but, want to make sure the tank is ready for them first.
Any Ideas? Could it be somethihng other than ICH? Should I try a new tang?
P.S. I do not have a Q tank and have no room for one.

 

[beth]

You should wait 30 days before adding any new fish, or you may just be sorry. Don't be suprised if you see the fish you have come down with ick, too.

 

[overfeed]

Use copper-safe, Fish with weak immune system will contract ich. If your setting up a fish-only tank, use this. But otherwise , it is not recommended. This will wipe out all major ich`s. I used to have problems with ich, even with damsels or any other hardy fishes . Its now been 2 months since my new set up(with copper-safe), not a single white spot ! <img src="graemlins//mischievous.gif" border="0" alt="[Mischievous]" />

 

[wamp]

The question was, what other parasites have the same symptoms of ICH are actually not?
Are there any?
The problem I have with the ICH diagnosis is the speed at which it spread to the other tang and the fact that no other fish showed signs of it. Seems to me that if it were ICH others would show at least some signs of infection. Plus, as stated, fish with and immune problem are more apt to get it. I though it was an external parasite? If it was external, like a skin problem, why would the fish die so quickly?
I guess I need to do some serious research...