Ultra Violet (UV) clarifiers

UV clarifiers are a wonderful innovation, to clear green water, developed from drinking water treatment plants. A thin film of water is passed over a UV light source that destroys the suspended algae that causes green water, the algae is broken down by a filter and the pond remains clear.

The UV bulb is normally housed in a quartz tube as glass would not let all UV light through, quartz is brittle so take care when handling. UV bulbs rarely go out but they do fade and hence, become less effective with time. A good policy to keep clear water is to change the bulb in early spring each year or if you want to stretch its life, keep a spare bulb handy and change it immediately the water starts to go green.

The correct wattage and design of bulb must be fitted. Never look at the UV light as it can damage the retina of your eye. Clarifiers have a means of checking the bulb is working without having to look at the naked bulb.

Where a UV clarifier is integral with a filter its strength will be appropriate to the pond size. When adding a UV clarifier to an existing filter system allow at least 8 watts for every 4500 litres of pond volume.

Power consumption of UV clarifiers is so low that they are a must on all pond systems. An 8watt unit would cost less than £6 a year to run