what is a wiper on a uv? i am picturing a winshield wiper type contraption, but i'm sure that is not correct.

You're pretty close actually... What a wiper on a UV sterilizer is, it is a circular plastic ring that goes around the quartz tube in the sterilizer. The plastic ring is attached to a stainless steel rod that extends out through the end of the sterilizer. To clean the quartz tube you just pull the rod out and push it back in and the plastic ring scrapes any buildup off the quartz tube. I have an Aqua 25 watt UV sterilizer with the wiper option and it really does work pretty good.

Rick

GOOD JOB RICK I HAVE TWO OF THESE UV'S THEY DO GREAT. LIKE RICK I HAVE TWO 25'S. GREEN SLIME GROWS ON THE GLASS WIPER CLEANS IT OFF SO THEY GIVE OFF THE FULL WATTAGE. OTHER WISE YOU LOSE POWER BECAUSE OF ALGAE. :goldfish