Pool Maintenance: Recognize These 4 Types of Algae

Posted March 30, 2023 by in Home

As a pool owner, one of the most important things you’ll need to be aware of is the presence of algae in your pool. They can multiply and become difficult to eliminate once it takes hold. Ultimately, they become a nuisance, making your pool look dirty and uninviting, and can even pose health risks if left untreated. To prevent the growth of algae in your pool, it’s essential to maintain the proper chemical balance. If you notice that the pH level in your pool is too low, you may be wondering how to raise pH in a pool. Fortunately, there are many simple and effective methods to raise pH levels, such as adding soda ash or sodium carbonate to your pool water.

Let’s take a closer look at the four most common types of algae that can grow in your pool and how to recognize them so that you can treat them quickly so you can enjoy your summer:

1. Black Algae

Black algae are the most challenging type of algae to get rid of in your pool. Typically, they start as small spots, barely visible to the naked eye, but can grow quickly to the size of a dinner plate. These colonies can anchor themselves to porous surfaces like tough plaster, where they develop extensive root networks beneath the pool surface, often between the plaster and concrete. Once they take root, black algae become visible, indicating that they are already firmly established.

Brushing off the visible portion of black algae in pool does not guarantee that you will destroy the entire root system. This means pool owners must take preventive measures to keep black algae from taking root in the first place.

2. Green Algae

Green algae is the most common type of algae found in swimming pools. It can grow rapidly in warm, sunny weather and turn your pool water green in a few days. You may notice a slimy film or patches of green on the walls or surface of your pool, giving the water a green tint

In severe cases, the concentration of algae can obscure the pool bottom and steps. Usually, this happens suddenly within 24 hours, especially during the summer months. To treat it, you’ll need to shock your pool with a high dose of chlorine and brush the affected areas to remove the algae.

3. Yellow Algae

This appears as small, yellowish-green spots on the walls and floor of your pool. It can be challenging to get rid of because it can cling to surfaces and hide in crevices. Since it is resistant to chlorine, you’ll need to use a specialized algaecide specially made to kill this type of algae. Alternatively, you can scrub the affected areas with a stiff brush or use other natural ways of controlling algae.

4. Pink Algae

Pink algae, a rare variety of algae that appears in shades of pink and red, actively thrives around pipe fittings and light fixtures on the surface of pools. This type of algae is unique in its coloration and infrequent occurrence. Typically, it grows around pipe fittings and light fixtures on the surface of pools. To eliminate it, you can use algaecides specifically designed for pink algae.


By recognizing the different types of algae that can grow in your pool, you can take the necessary steps to prevent and treat it, ensuring that your pool stays clean and inviting all season long. Be sure to take care of pool algae as soon as possible or schedule regular pool maintenance so experts can help you.