i have one i am not even running with the uv sterilizer they kill pretty much everything that goes through it. alage particles, plantkon for food, etc. the UV sterilizers don't care. i had problems with alage ran one and it helped clear that up, but this can be done also by reducing feedings/ and light as well. when feeding the corals you have to shut down the uv to keep the food alive long enough to be eaten etc.