It does ... but it's worse than useless. It's 9 watts and the SunSun claims a 525 GPH flow rate. That's 350 % beyond a 9-watt U/V's capability to even control simply free-floating algae. That U/V is a marketing gimmic only - the SunSun pumps way too fast and the organisms don't get enough exposure to the U/V to do anything. But SunSun has a lot of people spending money on replacement bulbs every six months - for a U/V that does nothing.