Why am I getting black mold in my pool?

Bracha Moskoff
by Bracha Moskoff

I've noticed these black spots forming in various areas of my pool, and I suspect it might be black mold. Is this possible?


If you've had experience dealing with black mold in a pool or have successfully eliminated it, I would greatly appreciate your assistance.


Any information you can provide would be appreciated.


Thank you so much

Black mold in pool

  13 answers
  • William William on Jun 25, 2023

    More likely algae growth. Black mold would not grow under water. It needs moisture and something organic to feed on.


  • Janice Janice on Jun 26, 2023

    It is important to test the PH level of your pol every 3-4 days, especially in hot weather and use the appropriate chlorine mixture to keep the pool in balance. The links William provided includes great info that I won't repeat.

  • It's probably algae. Have you tested the ph of the water?

  • Kathy Gunter Law Kathy Gunter Law on Jun 26, 2023

    Black mold would be highly unlikely. Check with your pool product supplier for a testing kit that will help you correct the issues that cause algae growth, which is most likely what the issue is.

  • Johnavallance82 Johnavallance82 on Jun 26, 2023

    Humidity is the cause. You need more ventillation or a dehumidifier!

  • Dee Dee on Jun 27, 2023

    With the extream heat we have been having a lot of my neighbors are getting the same thing. It is not mold it is algae. My neighbors have been using Clorex Pool and Spa treatments.

  • Redcatcec Redcatcec on Jul 01, 2023

    This is more than likely algae since it is underwater. You might want to get the pool water tested and treat, your local pool supply stores can do this and have the recommended supplies to fix the problem.

  • Mogie Mogie on Jul 01, 2023

    Like all algae, black algae flourish in water, where they can photosynthesize and easily multiply. Growth is particularly common in pools with pH imbalances, low chlorine levels, and poor water circulation and filtration.

  • Theresa Theresa on Jul 02, 2023

    Shock your pool and then brush it away with your pool brush.

  • The spores of black algae can travel to your swimming pool on other objects. Wash pool toys and accessories in bleach and put your family's swimsuits through the washing machine to avoid reintroducing black algae to your pool. Shock your pool.

  • Bracha Moskoff Bracha Moskoff on Jul 16, 2023

    Thanks for the help everyone

  • BrentHubbard BrentHubbard on Jan 25, 2024

    I'm not an expert, but I can offer some suggestions that might help with the black spots in your pool. While I can't say for sure if it's black mold, it's crucial to address any concerns promptly to maintain a clean and safe swimming environment.First, it's a good idea to visually inspect the affected areas and see if the spots can be easily brushed or scrubbed away. Sometimes, these spots could be caused by organic debris or other factors that aren't mold-related.If the spots persist and you suspect mold, it might be wise to consult professionals who specialize in mold remediation. They have the expertise to assess the situation accurately and can provide guidance on how to eliminate the mold safely.

  • Betsy Betsy on Jan 25, 2024

    Hi Bracha: I'd have someone look at it who is experienced. If it's black mold, you don't want to fool with it because when anyone is in the water, the mold spores can get into their eyes, nose, ears and mouth and cause serious damage.