A frequent inquiry by pond owners is on how to deal with algae growth. There are different types of algae and all of them can cause problems in a pond by depleting oxygen levels and thereby affecting pond life. Whether you have a fish pond or wildlife pond built using either a preformed liner or a flexible rubber pond liner, dealing with algae is important.
Too much algae found on the surface of a garden pond is the consequence of an imbalance of pond water nutrients. Untreated algae will eventually form a scum on the surface of the water. Algae can be treated with an algaecide but this will only treat the symptoms and not the cause. The best approach is to restore the natural balance of the nutrients in the water and rack off the algae from the water surface. Aquatic plants should take-up no more then two thirds of the surface of a pond. If you have too few plants or none at all, too much sunlight will be enter the water and encourage algae growth.
Aquatic plants help to break down all the waste products that algae thrive on. Don’t overstock your pond with fish as this will increase the amount of waste products, which algae thrive on. In addition, don’t over feed fish. The presence of water snails will also help to control the algae levels. They have a very important role to play in the maintenance and upkeep of your pond, and unlike land snails, they won’t eat decorative plants. Snails eat algae and are like vacuum cleaners moving around the edges of ponds, pond liner surface and plants feeding. They tend to lay their eggs on the underside of lily leaves, so do be on the look out if removing leaves from your pond.
Note: the thin layers of algae that grows on rocks and the edge of ponds on the pond liner, are not the bad type of algae and so don’t require removing. Only the algae growth that covers the surface of the water should be racked off as soon as possible.