I had been very skeptical about UV clarifier's in the past, I purchased this product and installed it on 5/18. My pond looked like pea soup. My pond is 8000 gallons, and is almost completely clear today, 5/21. I have wasted a ton of money on algaecides, and nualgae, for years. Sometimes being successful, but most of the time not. I am sold, on this product, and havent had it in for a week. If I had to buy a new one every year, it would be worth it.

This is the best (also the highest watt I've had) sterilizer I have purchased ( about 4 in the past). It cleared up the algae in about 3 days and once again I can see the bottom of my outdoor water pond. I recommend it.

Great device cleared up my green water in 5 days. It was hooked to my small pump that circulates 1200 gallons an hour. Check out the before and after pictures.

After six months, I finally got this installed in my pond (waiting on my landscaper) and it leaked constantly. Got the leaks under control and within a week it leaked around the glass tube inside and burned out the bulbs and ballast. So.... I spent a bunch of money on a product that did not hold up to normal pressure and I still have green water. Of course, the window to return it is long past.

For many years I did what my parents did before me to clean the algae out of our pond and filters, remove the fish, drain, scrub everything down, then replace all the parts with fresh water. I added using chemicals and good bacteria, but none of that kept the algae blooms away in the worst times.This product started making a difference in mere hours and in three days it completely turned a 'pea soup' pond into crystal clear water, fantastic. The pond is just under 800 gallons with gold fish, Koi, and plants. My filter is a large tub filled with large scrubber pads emptying into an 18" waterfall. I actually hooked the UV light up to a separate pump, pulling water right out of the pond, through the UV and directly back into the pond. Now that I know how well it works I will hook it up directly in line with the pond pump, feeding the filter and waterfall. The only 'con-ish' thing I can say so far is that the instructions are a bit simplistic. Once you know what you're doing they're fine, but with all things new the more info the better. I would recommend this product for sure.