If you are treating with hyposalinity as compared to chemicals then no... as far as ick, not all that much esp, since that is the ONLY way you will keep the ick from going dormant, aside from leaving a fish in the tank. UVs haven't been show to kill dormant ick but then again they haven't been shown to NOT kill dormant ick.... I honestly don't really care for UVs all that much so I can't tell you how effective they will be on the dormant ones.... in all reality probably not all that effective. I have heard that dormant ick can handle being dried up for short periods of time. Amyloodinium is marine velvet, scourge of the reef keeper. One of, if not THE hardest parasite to erradicate. It can handle SG all the way down to fresh water, can live off light indefinetly and attacks the gills and lungs before anything else, sometimes a fish is dead before you know it has velvet.... Copper and acriflavine are the only ways to go with velvet, at least with darn near 100% effectiveness. Granted people try all sorts of methods, flushing the system, no light, so on and so forth. Like nano stated it is FAR easier for a fish to go to lower SG than to go to higher SG because HIGHER is very tough on the osmoregulation. You can drop the salinity fairly quickly. Good luck!