How To Remove Algae From A Pool


On a hot summer day it is so nice to take a dip in your nice cool swimming pool. But when you go outside and find that your pool water looks green, a swim will be very unappealing. What is the culprit for that murky green water? None other than a pool owner’s nemesis… algae.

Many pool owners have battled with algae at some point. It is an annoying problem but with the right techniques, you can win the battle against algae. Before discussing how to get algae out of your pool, we must first learn a little more about algae.

What Is Algae?

According to the Department of Ecology of the state of Washington, algae are “primitive, primarily aquatic, one-celled or multicellular plant-like organisms that lack true stems, roots, and leaves but usually contain chlorophyll.”

Types Of Pool Algae

  • Green algae. These are the most common kind of algae found in pools. The surface of the pool and walls of the pool will have a bit of a slimy feel. The water will look murky and you won’t be able to see to the bottom of the pool. The water will look green. Green algae can also be seen floating on top of the water. Green algae are the easiest kind of algae to get rid of.​
  • Yellow or mustard algae. Yellow algae grow on the sides of the pool and in the shady crevices. Yellow algae have a powdery appearance. It is resistant to chlorine and therefore difficult to get rid of.
  • Black algae (also called blue-green algae). These are the most uncommon kind of pool algae. They will appear as black spots on the sides of the pool. These kinds of algae are very hard to get rid of because even though you may kill the superficial layer, its roots will have already grown into the walls of your pool.
  • Pink “algae”. This is actually a kind of bacterium with similar properties to algae. It grows in shady crevices of the pool and at the edge of the pool’s water line. It appears as small pink spots. When caught early enough, pink algae are generally not too difficult to remove.

What Causes Pool Algae?

Algae spores are carried into pools by wind and rain. They can also enter the pool if someone gets in with a swimsuit or gear that is contaminated with algae spores. Without proper sanitizing agents, the spores can easily multiply. When it is hot and sunny, algae can grow quickly. Algae thrive in stagnant water.

Are Algae Harmful?

In general, pool algae pose no immediate health risks. If left unattended, however, the pool can become a breeding ground for harmful bacteria like E-coli. Algae do pose a safety risk for swimmers because they cloud the water and limit visibility.

How To Get Rid Of Algae In A Pool

  1. Remove debris. Before removing algae from your pool, you will want to prep the pool first. You want to get rid of as much debris as possible, so start by skimming the water with your net. When debris like leaves and bugs are left in the pool, these will minimize the effect of the sanitizing agent that gets rid of the algae.​
  2. Clean the filter. After cleaning the filter, set the circulation to run for 24 hours a day. This will ensure that the pool will be able to clear out the algae from the pool after you use the sanitizing agent.
  3. Check the PH. In order for the chlorine to work effectively as possible to kill the algae, the PH level needs to be between 7.2 and 7.6. Alkalinity should be 80-120ppm. Adjust the PH if necessary.
  4. Brush the surfaces. Brush your pool to loosen algae. Make sure to get in crevices and behind your pool ladder where algae like to hide. Use a steel brush if you have a concrete pool and a nylon brush for a vinyl pool.
  5. Shock your pool. Pool shock is used to sanitize your pool. It works by drastically raising the chlorine levels to kill off the algae. You will need 2 pounds of shock for every 10,000 gallons of water. You may need more shock depending on how bad the algae problem is. After 24 hours check to see if the condition of your pool is improving. If not, add more shock- 1 pound per 10,000 gallons.
  6. Add an algaecide. After adding an algaecide by following the product instructions, let your pool sit overnight. Brush the pool again.
  7. Vacuum. There will likely be a lot of dead algae in your pool so you will want to use a vacuum to get rid of it.
  8. Clean the filter again. There will likely be a lot of dead algae in the filter. Cleaning it will ensure the filter is working efficiently. Clean the filter regularly throughout this entire process.

How To Prevent Algae

  • Ensure there is good circulation in your pool.
  • Shock your pool weekly.
  • Regularly brush your pool’s surfaces.
  • Use an algaecide regularly.
  • Maintain a proper PH balance.

Dealing with algae in a pool is an annoying problem but it can be dealt with using the proper equipment and techniques. When using chemicals, make sure you read the product instructions carefully so that you do not harm yourself. Be sure to use the proper amounts of the chemicals as well.

Once you follow all the steps to get rid of algae in your pool, the water will become sparkling clean again. After having to remove algae, you will likely never want to go through this process again. Make sure to take measures to prevent algae from growing in your pool again.​

Click Here to Leave a Comment Below

Leave a Reply: