How To Remove Black Algae Spots In Your Pool

Those tiny black spots in the bottom of your pool that just aren't coming clean with the pool vacuum aren't stubborn dirt. It's most likely black algae spots, and while they can be very difficult to remove, it is possible. These spots arise usually in really warm conditions and with pools that don't have the right balance of chemicals. See below for instructions on how to remove these black algae spots and how to help prevent them from coming back.

Here's What You'll Need:

  • Pool brush/vacuum head
  • Algaecide
  • Chlorine


  1. Brush the walls and bottom of the pool with your pool brush/vacuum head to help loosen the algae. Algae can root itself to the walls and floor of your pool and can also be present in your filter system.
  2. Add algaecide to your pool and follow the manufacturer instructions. Your pool may require more or less algaecide depending on the size, so you may need to know how many gallons of water your pool holds.
  3. Allow the algaecide to work at loosening the algae and then vacuum your pool. You can vacuum your pool with the filter set to waste in order to completely remove the algae from your pool and prevent it from just blowing back into your pool.
  4. Add chlorine or shock to your pool; again, the amount will depend on the size of your pool. Be sure to read the manufacturer directions. When adding chlorine or shock to your pool, be sure not to do it when the sun is high in the sky. The sun will burn off your chlorine quickly. Instead, add it in the early evening.
  5. Next, test your pool's chemicals. Be sure the pH level, chlorine and alkalinity levels are at the appropriate levels. If they aren't, be sure to add whatever chemicals are needed. Chemical levels that are not balanced are what contributes to the growth of algae in the first place.
  6. Keep an eye on your levels over the next few days and be sure to continue to vacuum your pool every few days or when you notice it getting dirty.

To help prevent algae from growing and from coming back, be sure again to test your levels and add chemicals as needed. If nobody has swam in your pool for awhile, brush the sides and bottom of your pool just to keep the water moving around. You can also run the filter a little more often to keep the water moving and to trap debris in the filter basket, rather than the debris falling to the floor of your pool. If you have had algae in your pool once, be sure to wash any pool toys with a bleach/water mixture, as the algae can live on pool toys as well. Wash swimsuits and towels in hot water and bleach to remove algae spores from these as well.

Contact a service like Celebrity Pools for more help.