Sterilization is the safest method of preventing and eliminating problems in an aquarium, or pond. UV will not kill a parasite on the fish, but parasites go through a free floating stage, at which point they are eliminated. Many of us reefers thought of avoiding UV, to keep plankton alive. However, with the skimmers and pumps used on aquariums the plankton population in the water column is virtually non existent. You can use a UV continuously (recommended) or just keep one at the ready, in the event of an outbreak. IMO, its just a matter of choice. I have one right now and been running it for 9 months (I already replaced the bulb 3 months ago, manufacturer recommend to replace bulb every 6 months). So far I didn't get any outbreak of ICK and my softies and corals are doing great. It also lower down thos nasty brown and red algae and for some reasons, the green ones tend to survive. I'm very happy with the results.
P.S. Water is crystal clear also.
Reuben.
