allpondsolutions 11w UV Light Steriliser for Pond & Aquarium - CUV-211 Fish Tank Pond Clarifier - Helps Remove Algae and Greenwater

I've had different shapes and sized ponds for 15 years now with a fairly high stock of fish and I've bought 3 of these over the years, they are a great product and last the distance, very easy to change UV bulbs which usually last a couple of years, only reason I had to buy a third one was because the garden flooded and submersed it and blew, that doesn't bother me as it does state that they are waterproof and are not submersible so remember to keep them off the ground. Always had them connected before my filters or before the bio media filter and I've had no algae or bacterial problems for years... It's great for ponds that use water pumps (Gravity fed drain systems are perfect but would still use these in my experience) as the tabulated system inside allows the water to stay in the UV chamber for longer without slowing down the water pressure allowing it to be exposed to the UV for longer to kill parasites and not just little bacteria or algae. With this style UV that has the tabulated system inside i would highly recommend it over just a clarifier. Considering it's a lot cheaper than the likes of an Evo clarifier and at a bigger wattage is a win win, nothing against Evo they are great products but these do the job perfectly for a lower price.

Nice product working well

Read the manual before buying.The Ballast is roughly 1m from the end of the cable, so shortening the cable is not possible.The device draws 29.5W, according to my wattmeter, during testing, and the ballast becomes mildly warm.The unit has its I/O in multiple directions, so do consider where it is to go. The Ballast is also reasonably large.The unit is elementary to put together and didn't leak - good.I will update the review in a week or so and comment on the water clarity.The viewports are useless in a UK summer sun. I will try them again later tonight.The best part by far is the transparent hose tail with the spinning propeller inside, showing water flow.Update 2 weeks later. My small 1000L pond is now crystal clear after being green for years. Fustratingly, I also a month ago improved by mechanical filtering, so this is not a scientific test.

Easy to set up and cleared my 2000 litre pond in a few days from pea soup to crystal clear.I had a 12watt uv that couldn't keep up..Happy with this purchase although I'm abit dubious on longevity to the type of plastic its made from.

The media could not be loaded. This was a fantastic buy. I have a 3000 ltr pond which was worse than pea soup.I was incredibly skeptical as to it's capabilities. I bought the UV for a 7000 ltr pond. It arrived quickly and it was reasonably priced. It has now been on three weeks .Today as well as seeing my fish ,for the first time in months I can see the bottom of the pond!!!!!! I would recommend cleaning the filter after about two weeks at most. I will clean it again next week and then just do it every 3to 4 months. Ps. I am not a robot !!!

My pond holds 4000 litres I bought this uvc to get rid of the pea green soup which was my pond water where I keep goldfish which I couldn't see anymore the cause was algaeI tried well none brands of algae remover but it didn't work after a month of treatment I know it can take up to a month to work successfullyTHIS ULTRA VIOLET CLARIFIER cleared my pond in 4 days I can now see the bottom of the pond and my beautiful fish friend'sOnly negative is i never took before and after picturesHighly recommended this product if you have algae problems and also shading the pond helps

My garden fish-pond had a severe attack of "green-water" (mainly blanket weed growth) following the winter, and the water had become nearly opaque. After fitting this steriliser in front of, and in series with, the pond filter system, the water was virtually clear within a week. I can now see the fish clearly right down to more than a metre below the surface. A very effective device. It's advisable, of course, to choose a model that's capable of dealing with the particular pond size it's used for. The UV light has the effect of killing and coagulating the blanket weed spores and cells.

Awful product, I had a clear pond, wanted to maintain that so bought this. Within 2 days the pond was murky and could hardly see 5 cms into it. Spend the extra and get a decent one from a shop.