I had one for several years. It did OK. I`m not going to give it all the credit as I fed my tank every other day and used only RO/DI water so I know that helped. The piece broke off that connected to my return line and made a mess but we survived. I have been UV free for a couple years now. I`m thinking it`s not really all that. Only the water that goes through the lighted chamber is what`s treated. The substrate where most of the parasites reside is not affected. If you have an algea bloom problem it does pretty good but I figure my everey other day feedings and RO/DI water help on that end. Saying all that I believe as far as UV`s that the turbo twist is the best out there. The twisting line that circles the UV light allows for more kill time as far as parasites and algea spores. Just not for me right now.