There’s algae and there’s black algae — while you don’t want either in your swimming pool, black algae is considered the hardest to get rid of. How to get rid of black algae in the pool is a question many do it yourself pool owners ask the pool pros at SwimRight Pool Service and Repair.

Black algae has deep roots that once they take hold, they dig in — especially into concrete or gunite pools and even when you remove the surface layers, there may still be roots or spores lingering in the nooks and crannies of the plaster. Black algae is most often found in dark areas of the pool.

How to get rid of black algae in the pool

Ridding the pool of black algae may be a task best left to the swimming pool service professionals because this algae can survive even abnormally large levels of chlorine being added to the water. Black algae is aggressive and tenacious and you need to be aggressive getting rid of it, too.

Black algae typically comes from the ocean so if you’re in a bathing suit you could bring it into your swimming pool. It is rare, but it might be blown into your pool water during monsoon season.

  1. You will need to sanitize everything that comes in contact with your pool water. This includes: rafts, brushes, buckets, lifesaving equipment, bathing suits, pool equipment and everything else that will get into the pool water. Wash suits in hot water and put in the dryer. Use diluted bleach to wash all pool floats and toys. Get a new scrub brush for the pool walls or thoroughly clean the brush you have before you put it into the pool water.
  2. Test the pool water chemistry. The chemistry levels need to be kept in line in order to discourage the growth of algae — black or otherwise.
  3. Brush. Brush. Brush. You will need to brush your pool walls and floor then brush them again. After you’ve brushed them a few times, brush again. You need to loosen the black algae then vacuum it out of the pool water.
  4. Even after the pool has been super chlorinated (see the next step), you will want to continue brushing it until you’re sure the algae is gone.
  5. Plan for triple shocking aka super chlorinating, the pool water. Your contractor wlil use three pounds of chlorine for every 10,000 gallons of water in your swimming pool. Shock it at night, then run the filters 24 hours a day until you’re sure the black algae has been cleared up.

The best way to protect your pool is to keep black algae from growing. We know this sounds obvious, but sometimes, no matter how often you clean and test the pool water, algae happens.

  1. Make certain you test the pool water chemistry often and keep chemicals in proper ranges
  2. Run the pool pump and filter for up to 12 hours a day. Ask us how many hours a day it should be run.
  3. Clean the pool regularly and thoroughly.
  4. Shock the pool weekly.
  5. Make sure you clean off pool equipment, especially if any pool equipment, toys or cleaning items are left out in a duststorm or rain storm.

If you see algae, call us. Let us help get your pool back to swimmable!