A U.V. sterilizer unit is always a great insurance policy to have! There is absolutely Nothing wrong with having one run! Just so we are on the same page though, A ultra violet sterilzer is a canister that water runs threw that a U.V. light bulb sits inside of. you cannot look at true U.V. light, it will dammage your eyes. if you have a tank under 200 gallons a 25 watt unit will work Great! the best brand names are "AquaUltraviolet" and "LifeGuard"