UV Lights in Backyard Ponds

Ultra violet (UV) lights are a popular addition to garden ponds in the hopes that these lights will produce cleaner water and solve algae problems.  In reality, these lights have a limited role in aiding your pond water quality.

The ultra violet sterilizer is a light that is encased in a sealed quartz tube within a stainless steel tube that allows pond water to flow around the bulb and exposes all of the pond water to the UV light.  UV radiation is a natural sterilizer that kills many organisms, including bacteria, viruses, microscopic algae, zoo plankton, and amoeba.  The sterilizing effect is dependent on how fast the water flows past the bulb and how powerful a bulb one has.  The longer the organisms are exposed to the UV light and the more powerful the UV light, the more organisms die.  While it does kill these organisms, they still need to be filtered out of the environment to maintain clean water.  Otherwise, these dead organisms will lead to plant or mat forming algal formation.

As one can see, UV lights can be quite beneficial in controlling diseases, green water (caused by planktonic algae) and some parasites.

However, it should not be used by itself in a garden pond.  It is a useful tool that can be added in order to clarify and control disease organisms in the garden pond.  However, one must still keep up with a mechanical and biological filter in order to make your garden pond the best that it can be.  Adding beneficial pond bacteria is also a must in order to break down harmful materials in the water.