i don't know what i had with my clowns but after all my research i thought it was brook. did a freshwater dip twice and the film disappeared and they recovered. try the fw dip first! i think the first dip was 1 min and the next day i did a 2min dip...snatched em up at night while they were sleep as to not stress em as much. mine were tank raised too from tony (ocreefmadness). he recommended the fw dip first after i texted him pics of the diseased clowns.