UV Sterilizers

Stronger than UV Clarifiers

UV sterilizers perform similarly to UV Clarifiers by emitting ultraviolet light to kill harmful pond algae and disease organisms, but with a higher efficiency. The more potent UV sterilizer can kill up to 99% of algae and harmful organisms in a fish pond, excluding the beneficial bacteria that grow on rocks or in the filter.

What is referred to as beneficial pond bacteria helps to maintain a healthy pond environment for goldfish, Koi, frogs, water snails, plants and other occupants of your fish pond. As pond fish eat plants and deposit waste, the bacteria convert it into deadly ammonia. The beneficial bacteria in a garden pond convert toxins into harmless nitrates and nitrogen, which in turn fertilizes the pond plants for the fish to eat. Without beneficial bacteria as fish pond would become toxic and unbalanced.

UV sterilizers are installed between the pond pump and filter. A UV sterilizer prevents free-floating algae from overgrowing the pond and sending the pond environment out of balance as the water warms up. This algae imbalance is something that typically occurs in springtime as the water warms up. UV sterilizers kill that algae and keep the pond's water balanced. They are also helpful in controlling fish diseases. The dead algae are collected by the UV sterilizer's biological filter. However, if your fish have parasites on their bodies, the UV sterilizer will not be able to kill them. The sterilizer can only kill floating parasites. Also, if the water runs too quickly there is a chance the sterilizer won't have the chance to kill the bacteria effectively.

When purchasing a UV sterilizer, there are things to consider like the correct size it requires to be efficient. A bare minimum guideline is:



Size of Pond

Gallons Per Hour


1000 Gallon



2000 Gallon



4500 Gallon



9000 Gallon



UV sterilizer bulbs lasts for approximately one year or 8000 hours. The bulbs lose efficiency over usage so must be replaced yearly. For safety, do not look at the UV light directly, it can damage your eyes. UV sterilizers cost between $160 and $1150 online.

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