[Myka]

I voted for all the answers. On my own reef I don't use UV at all, I have no reason to. On my client tanks I have some that don't use UV, some that use UV part-time, and some full-time. Depends on each tank, and also the client too (I put big UV sterilizers on tanks where clients add non-quarantined fish). I like to have a UV sterilizer available to use on tanks that have Tangs so the UV can be switched on if there are any Ich spots noticed on any of the fish. In order for UV to be effective for Ich, it has to be a big UV though, and there is a significant cost associated with a piece of equipment that is only used part-time.