How to Kill Algae Without Raising pH in a Pond


Algae is common in most ponds, however, in some ponds it can spread until it is out of control and makes a significant impact on a pond. It can block light that other water plants need to photosynthesize, and it can also drastically reduce oxygen levels, leading to fish dying off. While some herbicides are effective at removing the algae, they can raise the pH level of the pond. This can have other ill effects on the ecological balance of the pond. Instead, use natural ways to remove the algae and leave your pH unchanged.

Step 1

Rake or skim the algae off the pond's surface. Take a boat out into the pond to reach the algae you can't reach from shore. You can store it in a 5-gallon bucket and dump it out when you get back to shore.

Step 2

Add floating plants like water lilies, water hyacinth and water lettuce so they cover 50 to 75 percent of the pond's surface. Add submerged plants like anacharis to absorb excess nutrients from the water.

Step 3

Add barley straw to your pond at a rate of 1 bundle per 1,000 gallons of water to further filter out excess nutrients.

Step 4

Add an aerator to your pond to promote water circulation and movement.

Step 5

Leave a 10- to 20-foot strip of unmowed grass around the pond. This grass will absorb excess nutrients before they run into your pond.

Step 6

Prevent geese, livestock or other animals from hanging out near or in the pond water, as their waste can contribute to algae growth.

Step 7

Remove dead fish from your pond--especially if a larger fish kill occurs. Large amounts of fish decomposing in the water will intensify algae growth.

Things You'll Need

  • Pond rake
  • Skimmer
  • Boat
  • 5-gallon bucket
  • Floating plants
  • Barley straw
  • Aerator
  • Net


  • Natural Solutions, Etc: Pond Care Do's and Don'ts for Algae
  • Cornell University: How to Prevent and Control Pond Algae in Farm Ponds
Keywords: kill pond algae, prevent ph rise, removing pond algae, remove algae naturally, keeping ph stable, pond ph level

About this Author

Robin Gonyo has been writing for several years now. She has a deep love for gardening and has spent a vast amount of time researching that subject. Previously she has written for private clients before joining Demand Studios. She hopes to share her knowledge with others through her writing.