How to treat 'ich' also known as the freshwater whitespot disease

Ichthyophthirius Multifiliis, is a common disease of freshwater fish. It can be fatal if not treated.

'Ich' is a parasite that often appears as White spots on the fins and gills of the fish, roughly the size of a pin head. There is a theory that all fish have it and only become infected when stressed, I do not know if this is true. First, set your aquarium degrees up to a higher temperature as this will speed up the life cycle of the parasite, but only do this if your fish tolerate high water temperatures. Chemical treatments include formalin, malachite green, methylene blue, chelated copper, copper sulfate, potassium permanganate and quinine. You can by a treatment from your local pet store. My fish have just been cured of 'ich', but I did lose a few so  be prepared. 

References: http://en.wikipedia.org/wiki/Ichthyophthirius_multifiliis