Algae can be the bane of a summer pond gardener’s day. Sitting by the pond, the gardener notices a green or brown substance floating in the water. The pond water is murky. That beautiful green of the pond is actually algae, and it has taken over the pond. What is a gardener to do?
While small amounts of algae make good food for baby animals like tadpoles, an algal bloom can reduce light levels in the pond and will eventually decompose, using pond oxygen in the process. In the heat of summer, it is important to control pond algae levels.
Maintain a Good Bacterial Balance in the Pond
A balanced pond ecosystem is much more likely to stay in balance. Water gardeners do not need to spend every moment scrubbing the pond or removing all of the water in an effort to control algae. In fact, keeping some of the water is important, since it also contains beneficial bacteria.
Remove Nutrient Sources to Control Algae
One of the sources of algal blooms is too many nutrients. Be aware of the number of fish in the pond. Since these fish do not rely on natural food sources, it is possible to overstock a pond quite substantially. However, the leftover food and feces from the fish all contribute to nutrient-rich pond environment that is ready for an algal bloom. Leaves are another seasonal source of nutrients. To control fall leaves, use a combination of a seasonal pond net and pond filter to avoid having the nutrients from leaves join the pond all at once.
Control Algae and Add Shade Using Pond Plants
Algae love heat and sunshine. If the pond is in a bright location, add shrubs around the pond, preferably shrubs that do not lose their leaves in the winter. These will make conditions more difficult for algae.
Pond Filters Help Remove Algae and Clean Ponds
First, use a pond tool to remove mats of algae from the surface of the water. Use pond filters as additional algae control. Mechanical filters will collect some of the algae. More advanced filters like ultraviolet filters will actually kill the algae cells, since the low-level UV radiation damages the algae.
Natural Algae Killer
It is possible to add natural algae killer products to the pond to control algae. Add beneficial bacteria to the pond in a granulated form. These bacteria will help control the algae population in the pond. Barley straw is an interesting and natural solution to control pond algae. The enzymes in the straw create low levels of hydrogen peroxide as they decompose. Ideally, add these to the pond in the spring so that there is time for them to begin their work.
Removing algae from the pond helps maintain good oxygen levels and a healthy environment for fish and other aquatic plants and animals. It is possible to control and remove pond algae without using commercial algae killers, making algae control safe for fish, wildlife, and children.
Tricia Edgar - Tricia Edgar is a gardener, environmental educator, and science writer from the Pacific Northwest.
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