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How to Get Rid of Phosphorus in a Swimming Pool

By Jonathan McLelland
Remove phosphates, which can promote the growth of algae.
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Phosphorus, also known as phosphates, is a nutrient known to enhance the growth rate of plants in water. An excess of phosphates within swimming pools may contribute to excess algae development. Part of having a safe swimming experience is to minimize the amount of algae growing in the water and along the pool floor and walls. Swimming pool owners need to reduce or eliminate the amount of phosphorous in the water.

Check your pool's chlorine level by purchasing a DPD Colorimetric Test, available at any pool supply store. This chlorine tester utilizes a color-coated system to determine the level of chlorine. After placing pool water into the test vial, add drops from solution R-0001 and R-0002. After adding the aforementioned drops, review the color found in the vial and compare with the color chart in the test kit. Do not add the phosphate-removal solution into the water if the chlorine level is below 3.0 parts per million

Purchase a phosphate remover with lanthanum carbonate as its main ingredient. Lanthanum carbonate trades ions with phosphate in the water to completely remove phosphorus from the swimming pool. This type of phosphate remover is available at any pool supply store.

Add the lanthanum carbonate phosphate remover into the pool according to the directions on the product. Typically, the amount of phosphate remover added to a pool is determined by the pool's water capacity and algae level. Carefully read the application instructions to prevent damage to the swimming pool.


Things You Will Need

  • DPD Colorimetric Test
  • Phosphate remover


  • Prevent excessive phosphorus from entering the pool by covering the water during rainstorms and immediately removing plants, leaves and other organic debris.
  • According to the website Allchlor, shocking the pool with high amounts of chlorine kills algae but will not reduce phosphates in the pool.


  • By not removing excessive phosphorus from the pool, you run the risk of damaging pool walls and making the water unsafe for swimming because of flourishing algae.

About the Author


Jonathan McLelland has been a professional writer since 2005. He has worked as a story writer and editor for the international sitcom, “Completing Kaden,” as well as a proposal writer for various production companies. McLelland studied communication and theater at St. Louis Community College.