Green water algae is a common springtime issue for any pond, regardless of how well balanced the pond environment may be. These algal blooms are generally of the suspended kind and will thrive in springtime. As the water warms up the growing conditions will rapidly improve within the pond. The increase of available nutrients exceeds the response capacity of your ponds planting and the fast growing algae will quickly exploit this enhanced growing environment.

The good news is that this phenomenon is most likely short lived. As the submerged plants of the pond begin to grow more actively they will begin to mop up much of the excess nutrients in the water. This effect, coupled with the surface plants, such as lilies beginning to shade the water’s surface will very quickly restrict the ability of the algae to grow. You will most likely find that the problem disappears equally as quickly as it appeared.

Understanding this natural cycle should give you confidence to not worry. It is very unlikely that green water will be any more than a temporary unsightly inconvenience. One thing to avoid doing is to change the water. Any benefits of improved water clarity will be very short lived prior to the algae returning with a vengeance. If you do have a filtration system in place, the addition of a UV clarifier will aid the clearing of the water without the need for chemical intervention.