Danner Manufacturing, Inc. 10-Watt Submersible Ultraviolet Clarifier, 02910

This UV filter works, but there are some strange issues with it. Hopefully my review will help other customers avoid the hassles I went through with this item.The inlet/outlet barbs on this filter are supposedly sized to fit 3/4 inch tubing; however, oddly, the barbs are significantly smaller than they should be, so tubing goes on, hangs loosely, and then falls off if you move the unit around much.In my experience with other pond products with barbs, barbs are designed to hold tubing quite snugly, without requiring the use of clamps (this is especially important if you have to open up the unit every month or so to do the recommended cleanings of the interior light cover, where clamps would be a major pain). There are no threads or any other way of securing tubing to this UV filter.The issue of how to attach tubing to the unit caused a great deal of confusion for me when I first got the product. I took it to several local pond supply stores to see if they could help me figure out if I was doing something wrong. The pond supply folks were as puzzled as I was about why the barbs did not fit standard 3/4 inch tubing. We tried other sized tubing, but nothing fit properly.I emailed the customer support people at Danner Manufacturing (the company that makes these filters). Their staff were entirely unhelpful. Eventually, the best they could manage in response to my request for instructions on how to attach the unit to tubing (and ultimately to my Pondmaster pump/filter unit), was to send me a sketch showing a UV filter attached to a pump (but no instructions or diagrams on how this was actually accomplished). This sketch was supposed to demonstrate that it was theoretically possible to attach the UV filter to other equipment. When I followed up with several emails asking them for details on -how- to attach the tubing, I received a message that they were researching what types of adapters were needed, but then a week went by with no further communication from them despite an additional query from me. At that point, in frustration, I gave up on receiving any kind of customer support.As the algae was continuing to build up in my pond and I was increasingly concerned for my fish, I decided to just try running the UV filter with the tubing loosely attached just to see if that would somehow be good enough. Lo and behold, when the UV filter is running, even if loosely connected to the pump via 3/4 inch tubing, a certain amount of suction occurs, allowing the tubing to stay connected (as long as you don't bump the UV filter or the tubing).What this means is that, if you have a person to help you (holding the pump and any other attached equipment while you hold the UV filter and it's tubing), you can lay all of your equipment into the pond carefully, being sure nothing gets disconnected in the process, and then turn on the pump and UV filter. If everything stays connected, when you turn on the UV filter and pump, everything should stay connected -- as long as you don't have big, heavy fish that like to nudge the tubing or any significant currents where your equipment is located.Personally, I find this to be a tedious process (which will have to be repeated each time I clean the UV light cover and/or my filter), and I don't appreciate that there were no instructions about any of this included with the product. I also did not find Danner Manufacturing to be at all helpful in resolving this issue.However, once I figured it out... the UV filter does do its job wonderfully! The pond is free of algae after about a week of run-time. I just wish I had known how to solve the installation issues and hadn't wasted so much time trying to figure this out.

I installed the Pondmaster 10 watt ultraviolet clarifier this last Friday afternoon into a 500 gallon above-ground fish pond that was pea soup green from floating algae; so murky that I couldn't see one inch into the water. I wasn't even sure if my fish were still alive. Installation was a tiny bit tricky in that the intake/outflow connections are 3/4 inch and my tubing coming from my 350 gph pump was smaller (closer to 1/2 "), and the spitter (mine is shaped like a fish and spits water back into the pond for aeration purposes) also had a tube attached to it that was about 1/2". I just went to Home Depot and bought a couple of step-downs in the irrigation aisle, and some 3/4 inch flexible tubing in the water garden section of the store and put it all together. I put a 3/4 " to 1/2" step-down coming out of the outflow of my pump, attached the 3/4 " tubing, ran it over to the fish spitter/aerator, installed the 3/4" tubing directly to one of the openings on the Pondmaster, attached a short piece of 3/4" tubing to the other opening on the Pondmaster, then attached another 3/4" to 1/2" step-down, then attached the step-down to the 1/2" tubing integral to the spitter/aerator. I plugged the pump and the Pondmaster into the outlet and....... voila it worked!That was Friday last week. Saturday and Sunday came and went and I thought I must have been ripped off because I saw no clarification of the pea soup. Monday came, still nothing apparent. Tuesday morning I noticed a definite clarity to the water; I could almost see the bottom! Wednesday morning dawned to nearly perfectly clear water. I could easily see the bottom of the pond and all my fish!!!The instructions say that you should have a pump that pumps all the water through the pond in 2.5 to 3 hours. Mine pumps faster than that so I was worried I would have to get a smaller pump (you want the water to move slow enough past the ultraviolet light to actually kill the algae) but it turns out my pump was just fine. The water was perfectly clear in 5 days.I highly recommend this product.

I was using algicide and a filter and still could not get rid of the green algae. Installed this ultraviolet light and the water was crystal clear within five days. Don’t even have to use the filter anymore. Love it!

Since this was my 2nd. one i had no problem with the bulb and glass sleeve to put together. The one i was replacing i had 3/4" hose to connect to the unit. I had New submersible sump pump i was using and new 1" black corrugated hose with i connected to the 3/4" hose with hose clamp. Than i ran outlet hose to top of my waterfall. The waterfall has 3 tiers for the water to fall down to. I just have to remember to order new bulb yearly and maybe new sleeve. I had NO problems with pondmaster unit. I still have box from first one from 2002 with order forms. Amazon is great also with the shipping and price is right. By the way the water is crystal clear from the unit. I'll be back when i need a 3rd. one.

i have been battling green water for YEARS, tried all sorts of chemicals, and barley and bigger filters and pumps, nothing worked. This cleared my water up in in just a few days, love that its in the pond (submerged, after the filter and pump before the fountain)