How do I stop my Pond Water Going Green? UV Steriliser

As many fish keepers would agree, one of the best ways of tackling single-celled algae, which causes ‘green water’, is by adding a UV Steriliser to your pond filtration system.

In short, a UV steriliser works by penetrating and breaking down the algae cell wall, allowing them to stick to each other. This causes the algae to flocculate, or clump together, enabling the pond filter to remove it from the water.  

The UV bulb inside the steriliser is attached to a quartz sleeve, which protects the bulb from the water, and the electrical components of the light are enclosed within a ballast and housing unit. In your pond the water is pushed slowly through the steriliser’s quartz sleeve by a pump, where high intensity UV light passes through the water. This sterilises the bacteria and microorganisms present in the water by breaking their cell membranes, or damaging their DNA or other organelles in the cells.

Some of our own-brand UV Sterilisers have a unique design which feeds the water through a special helix, meaning the water does not just run through the UV but spins inside; giving more exposure to the UV and providing greater efficiency before the water exits the outlet. We also have Stainless Steel UV's which is up to 30% more effective due to its reflective body.

In addition to destroying bacteria, ultra-violet sterilisers can help reduce the spread of free-floating algae, however whilst it will kill algal blooms, it will not actually eradicate them. A UV steriliser is not a replacement for good biological and mechanical filter, which is still necessary to physically remove algae from the water.

Choosing The Best UV Steriliser For Your Pond

It is important when selecting a UV steriliser that you choose a unit specifically for the flow rate of your pump and size of your pond; otherwise there will not be enough water turnover to kill off the unwanted bacteria and algae.