Pest Alert – Algae in Ponds

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Ponds are wonderful landscape features to have on your property. These bodies of water add beauty and value. However, ponds need to be managed.
Ponds can have many problems. Too many nutrients from runoff, weeds, algae or pollutants can all be pond issues. Sometimes ponds can be too shallow and too clear leading to plant and algae growth around the edges.
If your pond is too clear and too shallow around the edges, algae and plant growth can occur. Healthy ponds should be deep and have steep banks under water. Ponds should also have a healthy murkiness. The healthy dark murky color of ponds is caused by a phytoplankton bloom.
Phytoplankton are microscopic creatures that grow in nutrient rich water. Nutrients in water get diluted when we have rainy summers like the one from this last summer or if the pond source is an underground spring. Extremely clear ponds can grow weeds and algae.

If you have algae in your pond, you should try multiple approaches to get rid of it. 

First, remove all the plants and algae that you can with a rake. Get a hard-tined rake, drill a hole in the handle, and tie a rope. Toss out the rake and pull it in with the rope. This is laborious but can reduce the amount of algae in your pond considerably.
Second, deepening the edges of an existing pond to an incline of 2:1 helps control algal growth. A 2:1 slope lessens the amount of shallow areas penetrated by sunlight and limits algal growth. Sunlight that penetrates and touches the pond bottom less than 18″ deep can lead to plant and algae growth.
Lastly, algaecides are chemicals that kill algae in water. You buy algaecides locally at several local farm stores including Southern AG or online. In the mountains, be sure to test your pond’s pH prior to using copper products.
Some pond owners such as HOAs find it easier and more effective to hire a pond contractor to manage their pond.
Finally, here is our pond management publication if you would like to learn more about caring for your pond.