How to Clean Pond Algae

Keep the water moving with a pond pump. Algae thrive in stagnant water. Use a pump large enough to circulate half the pond's water per hour. If you keep large fish such as Koi in your pond, circulate all the water each hour.

Install a biological or an ultraviolet filter. A biological filter removes planktonic algae and organic debris from the water using beneficial bacteria to break it down so it is not available as nutrients to the algae. An ultraviolet filter employs ultraviolet light to kill the algae as it passes through it.

Scoop up the strands and mats of algae from the surface of the pond with a fine meshed net or your hands. Scrub the algae off the sides of the pond and water features with a brush. This method is very effective when used in conjunction with a filter.

Use an algaecide to kill pond algae. If you prefer a natural additive, add barley straw or barley extract to the pond water. Barley generates hydrogen peroxide as it decomposes that kills algae. It is non-toxic to fish and aquatic plants.

Remove leaves, dead plants and other organic debris from the pond with a fine meshed net. The decay of this debris provides nutrients for the algae.

Locate your pond in a spot where it will receive about six hours of sunlight per day. This is enough sunlight for aquatic plants, but not so much that algae will thrive. Locate your pond so that water from rain or yard watering cannot run into the pond. This runoff is another source of nutrients that will fuel algae growth.