This is a artical i wrote for another site so since i cannot link to it i'll copy and paste it here.
ICH is probably the most commonly encountered disease in tropical aquariums and every aquarist will have had dealings with it at some time in their fish keeping career. If caught early and treated quickly then it is very easy to cure and represents no more of a problem to your fish then a pimple on your face would you.
How do i know my fish have ICH?
The early symptoms of fish having ICH is fish flicking and rubbing themselves against the substrate and decor in the tank, the gills may appear redder than usual and small white dots the size of a grain of sugar will be noticeable on the body and fins.
The parasite has a 3 stage cycle of growth first appearing on the fish as a white dot where it feeds on the host, it then frees itself from the host and drops to the substrate where it divides and lastly the cyst explodes into upto 1000 free swimming zoospores which start the cycle again once they find a host. The parasite can only be affected by conventional aquarium medications while the parasite is in this last free swimming form.
How do i treat ICH?
When treating ICH first do a 50% water change and vacume to remove as many of the free swimming parasites and undivided cysts as possible. Next slowly raise the temperature of the aquarium to 29c to speed up the life cycle of the parasite and providing you have no scaleless or salt intollerent fish add aquarium salt at a dose of 1 tsp per 5 gallons of water which will aid the fishes recovery.
Next you MUST use a medication designed for the treatment of ICH and follow the instructions for use printed on the bottle, highly recomended are INTERNET NUMBER 6 ANTI WHITE SPOT PLUS and WATERLIFE PROTOZIN. Continue with the treatment until it has been 7 days since the last spots were seen.
Personally i have never lost a fish to ICH.