What is Pond Algae?

Suspended algae and string algae are two of the most common types of algae that can be found in ponds. “Green algae” (another name for suspended algae) are single cell organisms that reproduce at an accelerated speed, and because of their size they’re capable of sneaking through most filtration systems making them a frustrating pest for most ponds. If the conditions are right and your pond water is left untreated, suspended algae can turn a crystal clear pond into something much darker and murkier.

String algae or “hair algae” appears in long strings that attach to rocks and plants, and if left alone for too long the strings can become matted and tangled, causing issues for your pond’s filtration system.

Keeping in mind the importance of the role that algae play in your pond’s ecosystem is crucial to making sure you don’t get overrun (or rather, overgrown) by algae. There’s nothing wrong or harmful with having a small amount of algae in your pond or water feature, but it becomes an issue when algae growth gets rampant and complicated to deal with. When that happens, it’s time to think about treatment and prevention.


Why is there pond algae?

Before you start treating your pond, its essential to understand the causes of excessive algae growth. The growth of both types of algae can be boosted by direct sunlight or by a water imbalance caused by excess nutrients from overfeeding fish or even stormwater runoff.

In the early spring when the season and temperatures start to change, this might be a time where you notice more algae blooming across the surface of your pond’s water. This may be caused by water temperatures being too low for fish and aquatic plant activity but warm enough for algae to grow comfortably. When this happens, that means that the algae is the only organism contributing to the pond’s ecosystem, allowing it to thrive with no competition for nutrients. These pockets of algae however do tend to clear up once water temperatures rise enough for fish and plant activity. If the algae persists, there are various solutions to control and prevent future algae growth.

Treatment and Prevention

Building a foundation for successful algae control begins with simply cutting down the nutrients in your pond water that attract algae. Grass clippings, leaves, fertilizer and other organic debris should stay out of your pond water. Creating a barrier of vegetation around your pond is a fantastic and easy way to help keep these additional nutrients out of the water.

Installing and running a pond aeration system consistently can also help prevent the aggregation of nutrients. These systems work to advance water circulation, increasing the amount of oxygen in the water which is a massive benefit to the whole pond ecosystem. Aerobic beneficial bacteria thrive in water with higher oxygen levels, and since they consume the organic debris and nutrients that algae flocks to, this is a great natural source of algae prevention and control!

Adding aquatic plants to your pond helps shield the surface from direct sunlight, options like water lilies or hyacinths are beautiful choices in a wide range of colors that will create a gorgeous look for your pond while preventing algae growth. Aquatic plants also compete with algae for the nutrients in your pond water, leaving less for the algae.

The main objective of treating your pond against algae is to re-harmonize the relationship between your pond and algae, rather than eradicating algae completely. Water treatments such as an algaecide (like the one by Aquascape) are a perfect solution to an already existing algae problem, its good for fighting both suspended and string algae.

Things to remember

Its important to remember that some algae is a sign of a healthy pond ecosystem. But if your pond water starts turning green and murky, or clumps of algae start clogging your streams, then its probably high time to start considering treatment options and other preventative changes.

A super quick fix to clumps of algae is the hands on approach — by reaching into your pond and removing the algae by hand or with a tool. This works well for string algae, but the problem can quickly resume again. For assistance with algae removal or any questions regarding what to do, contact FNC Ponds.