Q: Should I turn off my UV light when adding water treatments, like Nature’s Defense®, to my pond?
Olivia – Blissfield, MI
A: Great question! The answer all depends on the kind of ultraviolet light you’re talking about – so let’s quickly go through the differences between a UV sterilizer and a UV clarifier.
UV Sterilizer: Cleans It All- Good and Bad
A UV sterilizer completely sterilizes the water – which means it kills anything and everything that floats past its path, including beneficial bacteria found in some water treatments. These units are effective at killing floating algae and harmful pathogens like parasites, but they kill the good stuff, too. We don’t recommend adding bacteria to your pond while using a UV sterilizer.
UV Clarifier: Targets the Green Stuff
A UV clarifier is different. It targets just algae and leaves the bacteria alone (as long as the unit is sized right for the pond). The clarifier uses ultraviolet light to destroy the reproductive ability of suspended green stuff. Dead algae then clumps together into particles large enough to be removed by mechanical filtration, leaving the pond cleaner and clearer. If pea soup water is a recurring problem for you, add a UV clarifier to your pond.
Optimize the Flow
If you use a UV clarifier, you can leave the light on while you use bacteria-based treatments, like those found in the DefensePAC® Pond Care Package. But just be sure the bulb and pump are sized correctly.
Bright Enough Bulb: For a UV clarifier to be most effective, the bulb needs to have a high enough wattage for your pond’s volume. All UV clarifiers are rated based on pond size. The larger the wattage, the larger the pond size the UV clarifier can handle.
Power to the Pump: The water needs to flow pass the UV bulb at the just right speed, so the pump size is important. If the water moves too quickly, it won’t kill the algae and it could cause the seals on the unit to malfunction; if it moves too slowly, it will kill the algae and beneficial bacteria. A great rule of thumb is to push the water approximately half of what the UV is rated per hour.
A convenient option is to try out an all-in-one unit, like the AllClear™ & SolidFlo™ Combo Kits. The mechanical and biological filter system comes with a built-in UV clarifier. When used with the SolidFlo pump, you’ll be well on your way to clear water.
One last tip: Keep the water well-circulated by running an aeration system, like one of the Airmax® Aeration Kits. Its diaphragm compressors and air stones keep the beneficial bacteria supplied with oxygen, as well as ensure every drop of water and every algae cell float past that UV bulb.
Pond Talk: When have you used an UV clarifier in your pond?