from the blog

Controlling Algae Growth in Your Outdoor Pond

Care and maintenance

September 30, 2020

Algae growth can be a serious problem for both indoor aquariums and outdoor ponds. In an outdoor pond, a limited amount of algae can lend your pond a natural appearance and it can also provide a healthy food source for your fish. If algae spreads too quickly, however, and if its growth is not controlled it can threaten the healthy balance you have worked so hard to maintain in your pond. To avoid having to deal with a sudden algae problem, take early and consistent steps to control and limit algae growth within your pond.

The Pros and Cons of Algae in Ponds

Algae are single-celled organisms that thrive in warm, nutrient-rich water. In an outdoor pond, algae are an essential part of the food chain. Algae subsist on the waste produced by your fish and, in turn, become a food source for your fish. In limited quantities, algae can enhance the appearance of your pond by giving it a more natural look but if it grows out of control algae can cover the surfaces in your pond with a green or brown slime. In addition to this slimy muck, algae can also turn your pond water an unsightly shade of green. This may reduce the clarity of your pond water and make it more difficult for you to view your fish. In addition to the aesthetic problems induced by its growth, algae can also deplete the oxygen supply in your pond water which will make it a stressful environment for your fish.

Factors that Contribute to Algae Growth

Like any aquatic plant, algae require nutrients to grow and if your pond provides an abundance of these nutrients you may experience a problem with algae. Organic matter and uneaten fish food settle at the bottom of your pond which will, over time, result in a build-up of ammonia and nitrate on which algae can feed. Direct sunlight is another contributing factor in the growth of algae so if your pond is not shaded by trees you may have trouble with algae. Though it can be harmful to your pond if too much algae is allowed to grow, most ponds experience a “bloom” of algae in the spring. In most cases, your pond will find its balance after a few weeks and return to its normal clarity.

Tips for Controlling Algae

Installing an adequate filtration system in your pond is an easy way to limit the growth of algae. Many pond filters utilize chemical filtration which helps to remove the wastes and toxins that would otherwise provide a food source for algae. Adding aquatic plants to your pond is another easy solution because plants will compete with algae for the same nutrients, thus limiting the potential for algae to grow and spread.  Introducing some floating plants like water lilies may also help to control algae growth by cooling the water and providing shade.

In addition to these measures, adding an EcoBio-Block Wave or nsM to your outdoor pond can be effective in clarifying the water and reducing algae growth. EcoBio-Blocks are made from natural zeolite and special cement that has been infused with special beneficial bacteria. Once the block has been installed in your pond it will release bacteria regularly which will work to break down organic waste into ammonia, then nitrites and then into nitrates. EcoBio-Block keeps water healthy which discourages the growth of algae. It also appears to encourage the growth of anaerobic bacteria, which changes nitrates (on which bacteria feed) to nitrogen gas. This product is a simple way to control algae and a great way to keep your pond water clean and clear with no extra effort required on your part.