How to Rid Your Pool of Algae

Sooner or later, regardless of the pool being newly built or not, you’ll come face to face with the algae-problem. When these aquatic plants appear in your pool, you know something went wrong with the water chemistry. Although not as easy to get rid of them as they appear, they can be dealt with in a relatively swift manner if you act fast, preventing their growth and reappearance. In this article, we’ll help you identify what type of alga you’re facing, how to fight and remove it efficiently, as well as the methods through which you can ensure it won’t return to your pool.

Know the Problem

Despite the different species variation in nature, the algae that grow in pools are of only five types. You can easily identify them through their color, as well as the color they make the water take. Therefore you can distinguish between green, black, pink, and yellow. Let’s discuss them in detail.


It takes its color from the chlorophyll pigment inside its cells and will take several tones of green, even going into the blue and yellow spectrum. Due to this, it will give the water an intense greenish color, with patches here and there, if it sticks to the walls, or a more blurred tone if it floats freely. Luckily, it contains no toxins that could become a health issue, but it will stick to skin and clothes if you wish to swim in the basin. Although on its own it is harmless, it creates a perfect breeding ground for other types of bacteria, like E.coli, which, in turn, can cause stomach problems.


Although part of the same family as the green one, this type is more resilient and harder to get rid of. It usually takes a powdery yellow hue, like turmeric or mustard, so it’s relatively easy to identify. Due to its aspect, it can be easily mistaken for sand, or simply a spot in the water. Although rarer than green, it is also a tad difficult to get rid of, as it loves to stick to several elements, including pool walls. It also attaches to toys, equipment, brushes, and swimwear, and it has a higher tolerance for chlorine.


Even though its name makes you think of pink seaweed, it is not related to the water-loving plants. It is, in fact, a bacteria that has a slimy armor around it which makes it resilient to external factors. Although rare, it prefers plaster-made surfaces and will attach itself on and inside these elements. Despite its strange color, it is easy to deal with, requiring few actions from your part.


Last but not least, the black menace is a pool owner’s worse nightmare. This type can easily invade all kinds of basins and doesn’t shy away from chlorine. In fact, it is completely unaffected by natural amounts of sanitizers, therefore making it quite a pain to deal with. It loves to glue itself to surfaces with high porosity, sticking its roots deep, to ensure an even harder removal.

How to Fight It

Now that you’re familiarized with the different algae types and how they present themselves, you’ll have an easier time distinguishing between them and acting fast against them. Although the overall removing process is relatively the same for all types, for yellow and black it will vary slightly, as these two tend to be a bit more difficult to deal with.

  • Step 1. Identify and prepare. If you have green or pink invaders, you’ll need the usual amount of shock treatment. For yellow and black, three to four times the amount of shock should suffice.
  • Step 2. Brush it away. Take a brush with telescopic handle and manually brush the basin, thoroughly scrubbing the walls, waterline, and floor. This will dislodge any particle stuck on the surface, as well as any roots glued to the area.
  • Step 3. Remove it. This can be done in two ways – either by manually vacuuming it away, or letting the filter and skimmer take care of it. The first is faster, but tiring, while the second although slower, it will require a filter change afterward.
  • Step 4. Sanitize it. In this stage, you can utilize the shock treatment for green and pink algae. For yellow and black simply add chlorine.
  • Step 5. Brush it again (black and yellow only). Once you’ve sanitized the water, clean the brush with chlorine, and use it again. Insist on the spots where the bacteria is still present, to ensure it’s disappearance.
  • Step 6. Shock it (black and yellow only). Calculate how much shock you need and multiply it by three or four times, then add it to the water. While you might think it is a bit excessive, remember that these types of bacteria don’t go away without a fight.
  • Step 7. Test and balance. Now that the alga has been dealt with, it’s time to test the water and rebalance it accordingly.

Prevention is Better

Instead of having to deal with these aquatic pests, it’s better to prevent them from getting into your pool. While many of their spores travel by air or are easily brought in by a wide array of possibilities, you can stop them from taking roots by following a strict cleaning program. A thorough weekly upkeep routine will keep them away and will preserve the clarity of the water.

  • Brush it on all sides, corners, and areas, especially if a part of the basin is located under trees, in shaded areas and away from sun rays.
  • Vacuum it either manually or by utilizing a robotic cleaner. They come in several styles, models, and types, so you have plenty of options to choose from according to your pool needs
  • Test the water and balance it. If the chemistry is carefully managed, the water will not only be sparkling clean and pleasant to look at, but it will be no place for bacteria to grow in, therefore no algae to worry about.
  • Ensure a good circulation. By keeping the filters, pumps, and skimmers clean and working at their best, your maintenance work will be cut short, and you won’t have to deal with unpleasant pathogens in water.

Final Thoughts

All in all, depending on what type of algae has appeared in your basin, there are different ways to deal with them. While some can be easily removed, others require a lot more effort from your part. So, the best method to deal with them is to prevent them from taking root in the first place. A good water balance and perfect circulation combined with regular upkeep will help you avoid water bacteria and pathogens.


  1. Angelo says:

    Will cleaning the pool regularly with a robotic pool cleaner help prevent the appearance of algae?

    • Carl Hudgens says:

      Keeping the pool clean with the help of a robotic pool cleaner ensures that algae won’t be an issue for you because the water and the surfaces of the pool will be free of debris and impurities.

  2. Edward says:

    I have yellow algae in my pool, and I want to get rid of this problem. How do you recommend I proceed?

    • Carl Hudgens says:

      To get rid of the nasty yellow algae that have appeared, we advise you to first clean the pool with a brush that has tough bristles. Afterward, turn on the pump and let it remove all the water in the pool. Next, fill the pool with clean water and add a potent algaecide that will surely eliminate this problem once and for all.

  3. Bruno says:

    Should I use a robotic cleaner if I used algaecide?

  4. Erik says:

    Can I swim with algaecide?

    • Becky Eddinson says:

      As you probably know algaecide is used to shock and kill algae using strong chemical compounds. Swimming during algaecide treatment depends on the type of product used. Some of them are safe for immediate swimming, while others can cause slight eye or skin irritation. However, it’s recommended to follow the manufacturer’s instructions, in order to avoid problems.

  5. Claire says:

    Hello, I have algae in my pool. Is it harmful to my body?

    • Becky Eddinson says:

      It is not exactly harmful. However, if there is not enough chlorine to kill the bacteria in algae, there might be a risk of infections.

  6. Darcy says:

    What is the best way to remove the algae out of a 10 ft above ground pool?

    • Becky Eddinson says:

      In order to remove the algae, you need to use flocculant and a vacuum cleaner that can vacuum the pool. If you still have any algae after, repeat the process the next day. However, do not with the amounts of flocculant as it is poisonous.

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