I have a UV steralizer on each of my three tanks, all reef. I have to add a little more phytoplankton, but the idea that I have perfectly clear, crystal clean water is worth it. The only ick I had was before I bought the steralizers. I have had them all for a umber of years and have never had a parasitic or bacterial infection. I also have never had anything die of malnutrition. Actually, I have never has an invert die. The parasite that causes ick live in the substrate only during their infant stage. Once they reach adulthood, they look for a host. That host is usually a fish with a compromised immune system. Lets face it, all fish are stressed out at one time or another, but even a stressed out fish can fight off a small attack from a parasite. The UV steralizer guarantees that an adult parasite will not reach your fish. The small amount that I spend on extra nourishment is worth much then dead fish, or worse yet, trying to catch the fish among 300lbs of live rock so that I can quaranteen them. Like I said, over 5 years with a UV steralizer, not one infection and never a loss of an invert. Show me the proof that a UV steralizer is bad for my reef tanks!