How Black Algae Gets Into Your Pool — And How to Properly Treat It

If you own a pool in the Sacramento area, you know how important it is to keep your water clear, safe, and inviting. But sometimes, even the most diligent pool owners run into stubborn issues like black algae. Unlike regular green algae, black algae can be much harder to remove — and if left untreated, it can quickly take over your pool’s surfaces.

At Provident Pools, we’ve helped countless Sacramento homeowners tackle black algae infestations and restore their pools back to sparkling condition. Let’s break down what black algae is, how it gets into your pool, and the best way to treat it.

What Is Black Algae?

Black algae is not actually an algae but a type of bacteria with chlorophyll, which allows it to photosynthesize. It forms dark blue-green to black spots on plaster, tile, or concrete surfaces. What makes it especially tough is its protective outer layer and deep root system, which allow it to dig into porous surfaces like plaster.

This means even if you brush the top, the roots can remain, causing it to grow back.

How Does Black Algae Get Into a Pool?

Black algae often makes its way into pools through:

• Contaminated swimsuits or equipment: If someone has been swimming in a natural body of water (like a lake or river), black algae can cling to fabric or gear and be carried into your pool.

• Poor water circulation: Stagnant areas are more prone to algae growth.

• Low sanitizer levels: Inadequate chlorine or poor chemical balance allows algae to thrive.

• Neglected brushing: Since black algae embeds itself into surfaces, pools that aren’t brushed regularly are more at risk.

How to Properly Treat Black Algae

Treating black algae requires more than just dumping chlorine in the pool. Here’s the proven method we use at Provident Pools:

1. Test and Balance the Water: First, ensure proper pH and chlorine levels. Balanced water allows chemicals to work more effectively.

2. Aggressive Brushing: Using a stainless steel pool brush, scrub affected areas to break through the algae’s protective layers and expose its roots.

3. Shock Treatment: Apply a high dose of chlorine shock directly to the spots. In severe cases, granular chlorine may be rubbed directly on the algae.

4. Algaecide Application: Specialized black algae algaecides help kill resistant spores.

5. Filter & Circulate: Run the pump continuously to keep water moving and allow chemicals to distribute evenly.

6. Repeat as Needed: Black algae can be stubborn — multiple treatments may be required. Consistency is key.

Why Work With Provident Pools?

Black algae is one of the toughest pool problems to handle on your own. At Provident Pools, we bring years of experience in eliminating black algae for Sacramento-area homeowners. Our technicians know the right balance of chemistry, brushing techniques, and follow-up care to completely eradicate black algae and keep it from coming back.

We don’t just treat the symptoms — we make sure your pool stays healthy, balanced, and algae-free.

Protect Your Sacramento Pool From Black Algae

If you’ve noticed stubborn dark spots in your pool that won’t brush away, don’t wait for the problem to spread. Provident Pools is here to help with expert black algae treatment and regular maintenance services.

👉 Contact us today at 916-954-1909

to schedule a service and enjoy a clean, sparkling pool all season long.