Your inverts should be safe as the parasite feeds exclusively on fish. This is a quote from Advanced Aquarist:
"Cryptocaryon irritans is a ciliated protozoan parasite of marine teleost fish in tropical and temperate waters. This pathogen is an obligate parasite of marine fish (Iwama, Pickering, Sumpter & Shreck, 1997. Dickerson & Dawe, 1994). This means that
it feeds exclusively on fish and cannot complete its life cycle unless this food source is available within its environment. The theront stage of this parasite will not survive for more than a day or two without a host fish"
http://www.advancedaquarist.com/issu...2003/mini1.htm