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Our UV sterilizers consist of a long-life ultraviolet (UV) lamp inside a quartz glass sleeve that is suspended in the center of a black plastic pipe. When pond water is pumped through the space between the quartz sleeve and the plastic pipe, the intense ultraviolet radiation emitted by the lamp effectively kills floating microorganisms, such as bacteria, viruses, molds, and algae, by breaking down their DNA molecules. The process is environmentally safe and does not leave any residue in the water.


uv with wiper

UV sterilizer with internal wiper and built-in unions


We recommend routine use of UV sterilizers in ponds with substantial fish populations as a means to control algae growth and reduce the spread of fish diseases. They are also effective for eliminating green water in any pond where other methods have proven unsuccessful. UV sterilizers can be used as the only means of water treatment in ponds with minimal organic matter and no fish, such as formal ponds with fountains, but when fish are present they should always be used in conjunction with mechanical and biological filtration to remove suspended organic matter or toxic dissolved organic compounds. UV sterilizers have no effect on string algae and other aquatic life that remain in the pond and do not pass by the UV lamp.

SELECTING A UV STERILIZER:  Our UV's use superior-quality, ultra-compact, high-output lamps. This allows both the enclosure and the quartz sleeve to be very short which reduces the likelihood of glass breakage and permits easy installation in tight spaces. A built-in wiper permits rapid cleaning of the exterior of the quartz tube without the need to open the unit, further reducing the risk of glass breakage. The inlet and outlet can be rotated to any angle, and both included built-in 2" unions. We can supply reducing fittings as needed to fit any size pipe or hose.

Performance of single and paired UV sterilizers with light, normal, and heavy fish stocking levels can be found in the chart below. For optimal results, the total UV lamp wattage must be properly matched to the pond size, and the water must not pass through the UV sterilizer faster than the maximum flow rate. We stock three UV sterilizers with lamp wattages of 15 watts, 25 watts, and 57 watts. When two 57 watt sterilizers are ganged together, the maximum flow rate and pond capacity are doubled; when four 57 watt sterilizers are ganged together, the maximum flow rate and pond capacity are quadrupled. Higher-wattage UV's are available for ponds of any size and pumps of any flow rate.

UV Sterilizer Specifications
Wattage Max Flow Light Stock Normal Stock Heavy Stock Length
15 w 700 gph 1000 gal 500 gal 200 gal 23 in
25 w 1200 gph 2500 gal 1200 gal 600 gal 26 in
57 w 3200 gph 5000 gal 2500 gal 1200 gal 26 in
2 x 57 w 6400 gph 10000 gal 5000 gal 2500 gal 26 in
4 x 57 w 12800 gph 20000 gal 10000 gal 5000 gal 26 in

INSTALLATION:   It is best to install the UV sterilizer between the filter and the pond so that water passes through the UV after it has passed through the filter and most of the organic matter has been removed. In this case, the UV must be positioned so that it is always completely filled with water. With gravity return filters such as waterfall filters and gravel filters, the UV sterilizer must be installed between the pump and filter, in which case it will always be filled. Whenever possible, all of the water that flows through the pond pump and filter should pass through the UV. However, if the UV wattage is sufficient for the pond volume but the desired pump flow rate exceeds the maximum flow rate for the UV, some of the water can be diverted around the UV using a three-way valve assembly.

MAINTENANCE:  Every few weeks, operate the wiper mechanism several times to clean the surface of the quartz sleeve, and verify that the bulb is functioning from the glow through the clear end cap. A UV lamp can last for many years, but the UV radiation it emits drops significantly as it ages. In cold climates where the pond is only operated from spring to fall, the bulb should be replaced every two years; in warmer climates where the pond is operated year-round, it should be replaced each year. The quartz sleeve can last for many years if it is handled carefully, and the UV housing has a lifetime warranty. At the end of each season, remove the UV by separating the unions, clean it thoroughly, and store it where it won't freeze.


UV Sterilizer, 15 watt, black, with wiper - $196.00
UV Sterilizer, 25 watt, black, with wiper - $272.00
UV Sterilizer, 57 watt, black, with wiper - $408.00
Replacement Lamp for 15 watt UV - $40.00
Replacement Lamp for 25 watt UV - $44.00
Replacement Lamp for 57 watt UV - $56.00
Replacement Sleeve for 15 watt UV - $40.00
Replacement Sleeve for 25 watt UV - $44.00
Replacement Sleeve for 57 watt UV - $44.00


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