How to Prevent & Clean the Green

The word even sounds like a spoiler of perfection, something prolific and powerful enough to taint something otherwise exquisite. Algae—a non-flowering plant often found in water—is a pond owner’s nemesis.

Algae—when kept in check—can be beneficial to the pond, providing a natural appearance and nurturance for fish and other inhabitants. But when conditions cause overgrowth, pond water can take on a dreaded green hue. Resulting oxygen depletion from excessive algae bloom can threaten the health of fish and plants.

Decisions made in the pond installation process are critical to preventing algae overgrowth. Ponds made of concrete, limestone or marble may have a higher pH, leading to increased algae growth.

To many pond owners, all algae is not created equal. String algae—visible on perimeter rocks or on the pond bottom—can create a natural, organic look. In small quantities, it’s benign and even welcomed. If string algae becomes excessive, it can be removed from waterfalls and perimeter rocks by hand. OASE’s PondoVac is the optimal tool for removing algae and other debris from the pond bottom.

Suspended algae causes water to appear green—verify its presence by scooping pond water into a clear glass. If the water is

Excessive algae—of either kind—is a sign the pond’s biological ecosystem is out of balance. Explore possible causes—rainfall, chemical runoff, excessive fish stock, sunlight or leaves are some of the usual suspects.

OASE’s AquaActiv products work to clean the green and restore the pond’s biological balance. The product line conditions, cleans, prevents and controls algae growth, restoring your pond’s beauty.

To prevent an influx of nutrients from decomposing leaves, remove vegetation promptly with OASE's EasyPick pond pliers. Installing a filter—such as OASE’s BioTec ScreenMatic² option—promises a healthy and algae-free pond.

The leaves of floating plants not only enhance the pond’s beauty, they reduce algae production by blocking sunlight. They also absorb nutrients—produced by fish—which contribute to an environment ideal for algae growth. Submerged plants absorb carbon dioxide and release oxygen, preserving the ponds cleanliness and clarity.

Fish should consume all food within 5 minutes of feeding. Any remaining food will decompose, adding to the nutrient load. High quality fish food is also beneficial, as more nutrients are absorbed through digestion.

We get it—controlling algae blooms is not an ideal way to spend a beautiful Saturday afternoon. But with a little effort—and the right products—your pond’s beauty will be restored. Pull up an Adirondack and enjoy the clean, clear water.