Hmmmmm well, I'm still in the process of setting up my tank so obviously I have no, zero, zip, nada experience to back this up but ... I've been researching this thing for about 9 months now and I have *never* seen anything about corals bringing parasites into the tank. Not that I've even scratched the surface of information/opinions out there but I've never heard of such a thing. I have however heard numerous stories of LFS' selling new hobbiest unneeded and even harmful equipment, additives, livestock and other sundry items. Personally, I think I'd wait until a few more experienced folks have jumped into this and given their opinions before I spent any money on a UV. Again, just my .02.
Later,
Paul