If you’ve never had black algae in your swimming pool, consider yourself lucky! Because plaster pools are so porous, they are are especially susceptible to the growth of black algae. Here are 5 tips for preventing and eliminating black algae in your swimming pool or spa.

Maintain proper water chemistry: Black algae thrives in high pH, high total alkalinity, and low chlorine levels. Keeping these levels in the recommended range (pH 7.2-7.8, total alkalinity 80-120 ppm, chlorine 1-3 ppm) will make it harder for black algae to grow.
Brush and Vacuum the pool regularly: Scrubbing the affected areas and vacuuming dead algae helps to remove the growth and prevent it from spreading.
Use Algaecides: Algaecides specifically designed to target black algae can be added to the pool water to kill the existing algae and prevent new growth.
Shock the Pool: Shocking the pool with a high dose of chlorine can kill black algae and other contaminants.
Implement a UV/Ozone sanitization system: These systems help to kill algae and bacteria in the water and can reduce the need for chemical treatment, making it harder for black algae to grow and thrive.

If you are fighting a losing battle with black algae, consider the ultimate solution: refinishing your pool with the Advanced-Glass fiberglass system, or EcoFinish! Both of these finishes provide a non-porous, inert barrier between the pool water and the pool plaster. They are much easier to maintain, help prevent black algae, and provide a much longer life than any other pool finish!