How to Get Rid of Algae in Water Features


Algae is a common problem in water features, such as ponds, waterfalls and fountains. Two main types of algae grow in water features: string algae and plankton algae. Plankton is the algae that grows in the water and turns it a pea-soup green, while string algae looks like green hair and grows along the bottom of your water feature. String algae are usually much easier to get rid of than plankton, due to the different conditions that cause it to grow. String algae grow where there is little water circulation, but plankton grows from an abundance of nutrients in the pond and sunlight.

Get Rid of String Algae

Step 1

Siphon out or otherwise remove all the water from your pond, waterfall or fountain. Empty the water feature completely.

Step 2

Sprinkle Kosher or non-iodized salt over the bottom and sides of the water feature. Be sure to cover all the surfaces where the string algae are growing.

Step 3

Allow the salt to remain on the water feature's surfaces for about three or four days. Then, scrub the surfaces with a medium-bristle brush.

Step 4

Rinse the water feature thoroughly to remove all the salt. Refill with clean water.

Get Rid of Plankton Algae

Step 1

Clean your water feature to remove all debris, especially any fallen leaves in the water. You can use a net or pond vacuum, depending on the type of water feature you're cleaning.

Step 2

Empty all the water from the fountain, waterfall or small garden pond. Scrub away any algae clinging to the sides or bottom of the water feature and refill it with clean water.

Step 3

Add beneficial bacteria to the water so that the bacteria can help to process fish wastes and other nutrients in the water that algae consume. Many beneficial bacteria products exist for water features, found at most aquarium or garden stores.

Step 4

Move your water feature into a shaded area to reduce the amount of sunlight exposure. If the plankton is growing in a pond, add some aquatic plants to shade the pond's surface area.

Tips and Warnings

  • If you're cleaning out string algae from a pond with fish and plants, be sure to remove them before emptying the water. Don't overfeed your fish in your pond, because the excess nutrients from uneaten fish food can cause plankton to thrive.

Things You'll Need

  • Wet/dry shop vac (optional)
  • Kosher or non-iodized salt
  • Medium-bristle scrub brush
  • Garden hose
  • Net or pond vacuum (optional)
  • Beneficial bacteria
  • Aquatic plants


  • How Do I Get Rid of the Algae in My Pond?

Who Can Help

  • Algae and Pond Weed Control Information
  • The Pond Guy Blog: How Do I Combat String Algae in My Water Feature?
Keywords: get rid of algae, water feature algae, clean pond algae

About this Author

Sarah Terry brings 10 years of experience writing novels, business-to-business newsletters, and a plethora of how-to articles. Terry has written articles and publications for a wide range of markets and subject matters, including Medicine & Health, Eli Financial, Dartnell Publications and Eli Journals.