Black Algae in Your Pool? Here's How You Can Rid Your Pool of Them

Black Algae in Your Pool? Here's How You Can Rid Your Pool of Them

Black Algae in Your Pool? Here's How You Can Rid Your Pool of Them


A shimmering pool is the epitome of relaxation during a scorching Florida day. However, that tranquil oasis can quickly transform into a battleground when black algae invades. To the dismay of pool owners, black algae is one of the most challenging pool pests to eradicate, with its stubborn resilience and notorious ability to return, seemingly from the dead.

Fear not, as we're about to share a battle plan to get your pool back to its sparkling best. Whether you're in Winter Park, FL, or soaking up the sun elsewhere, these strategies are your allies in the war on black algae.


Identifying the Enemy

Before you take up arms, it's essential to know your adversary. Black algae, or Nostocaceae, is a genus of microorganisms that typically begin their invasion as small, blue-green specks. Over time, they develop into large, dark green or black spots, often accompanied by a slimy texture.

Distinctive features of black algae include:

  • Roots or Thalli: Deeply rooted in rough pool surfaces, black algae develop a holdfast that's extremely resilient.
  • Cell Structure: Encased in layers of mucilage, black algae cells are protected from the chlorine and immune to many quick-fix pool chemicals.

Once you've identified these features, you're ready to take the first steps towards eradication.

Craft Your Battle Plan

Dealing with black algae is a two-pronged attack that requires patience and precision. Here's a step-by-step plan that will lead you to a black algae-free pool.

Arm Yourself with the Right Equipment

You'll need:

  • Pool Brush: A stiff nylon brush to scrub the algae off surfaces.
  • Telescopic Pole: To give you reach across the pool.
  • Pool Vacuum: For large amounts of dead algae, vacuuming is the best approach.
  • Algae Brush: Specifically designed for persistent algae.
  • Safety Equipment: Gloves and eye protection as a precaution.

Initial Brush and Scrub

Don't hold back. Use the stiff brush to scrub the walls and floor of your pool in any areas you suspect and beyond. Be thorough, and don't be surprised if this initial scrubbing takes time and effort—it's a sign that you're reaching those resilient 'roots.'

Shock Treatment

Now, it's time to hit hard with a chlorine shock. This high-dosage treatment is your best bet to penetrate through the cell layers and effectively kill the black algae. Begin with a concentrated spot treatment for each affected area before proceeding with an overall pool shock.

Follow up with Algaecide

Choose an algaecide specifically formulated to combat black algae. Apply it to the whole pool according to the manufacturer's instructions.

Continuous Maintenance

The war isn't over with a single treatment. Black algae often requires repeated upkeep. Make post-treatment scrubbing and shocking part of your pool maintenance routine. Diligence is key here; consistent care is the only way to ensure the algae doesn't return.

Avoiding Reinvasion

Once your pool is black algae-free, you must take steps to prevent a reoccurrence. Here are a few strategies:

  • Maintain Proper Water Balance: Black algae thrives in pools with imbalanced water conditions. Keep your pH levels in check and ensure adequate sanitation.
  • Regular Brushing: Get into a routine of thoroughly brushing your pool.
  • Monitor Pool Surfaces: Keep an eye out for the early signs of black algae. The sooner you spot it, the quicker you can act.
  • Use a Sequestering Agent: These substances prevent metals from staining pool surfaces and can deter the growth of black algae.

Through diligence and preemptive care, you can keep your pool black algae-free.

Partner with Professionals

Sometimes, despite your best efforts, the algae prevails. In these cases, it may be time to call in the cavalry. Professional pool services, like Pure & Simple Pool Care in Winter Park, FL, are equipped with specialized tools and expertise to deal with even the most resilient algae infestations. Their services can also include preventative measures to stop black algae in its tracks.

The Aftermath

Congratulations! You've fought the good fight and won. Your pool is now an algae-free haven once again. Whether you took a DIY approach or partnered with professionals, remember to maintain your vigilance. Keep treating your pool regularly, stay on top of your water chemistry, and enjoy your oasis, knowing you remain victorious against black algae.


In conclusion, while black algae may be daunting, it's not unbeatable. By understanding the nature of your enemy and deploying the right tactics, you can triumph and keep your pool pristine. If you're in Winter Park, FL, or any other location dealing with stubborn pool problems, reach out to reliable pool services today and regain control over your aquatic domain.

For more information on pool care, or to access our pool services in Winter Park, FL, visit Pure & Simple Pool Care.