Very few things ruin the thought of enjoying your swimming pool quicker than spotting algae. If you see algae, you will want to act fast. There are different types of algae and different causes, but getting rid of algae is a multi-step process. This guide will discuss algae and the most effective ways to clear it from your pool before it turns into an algae bloom. 

What Causes Pool Algae? 

There is no single cause for pool algae. But unfortunately, dirt, debris, wind, and rain can introduce algae spores. They can also enter the pool on toys, swimwear, or even animals that enter your pool after having been in natural bodies of water contaminated with algae. 

The more spores in the pool, the quicker it can become a problem as they multiply, grow on your pool walls, or become a full-fledged algae bloom. Following proper pool maintenance is vital for keeping your water healthy and making it less hospitable for algae growth. When your filters are dirty or clogged, or your chemical levels are out of sync, it encourages algae growth and other problems. 

Are There Different Types of Pool Algae? 

Algae is a primarily aquatic organism that obtains energy from sunlight, which is why it is easy for algae to flourish during warm, sunny weather. There are a few different types of pool algae that you are likely to encounter. You can usually identify algae by its color.  

Green Algae

The most common algae found in swimming pools is green algae. It will appear on a spectrum of green ranging from teal-green to dark green to a blackish-green color. It is a floating green form of algae that will make your pool surfaces look and feel slimy. Although it is the most common type of algae, it is also the easiest algae to kill. It does spread quickly. To rid your pool of green algae, you will need to vacuum, brush, shock, and filter your pool water. 

Yellow Algae

Yellow algae, sometimes called mustard algae or brown algae, is rare and is usually found in humid climates. You can identify yellow algae by its glob-like shape. It will look similar to pollen or sand, and you will find it lurking in shady corners of the pool. It will involve a lot of work brushing your pool and extra shock, which we will discuss further. 

Black Algae 

Black algae can be more challenging to clear up. It is actually a bacteria, and it roots itself into concrete, making it harder to kill. It will likely take several rounds of thorough cleaning and can grow back quickly otherwise. 

Pink Algae

Also called pink slime, pink algae is a misnomer. Pink algae is an airborne bacteria, not a type of algae. 

What Problems can Algae Cause? 

Algae doesn’t just make your water look bad. It can also cause a multitude of problems in your pool, which is why it is so important to take preventative measures. 

  • Germs – Algae can trap bacteria and germs, making the water harmful for you and your family. 
  • Clogged Filters – You may have noticed that algae clump up and reproduce quickly. This makes it hard for the pool’s filter to work efficiently. Black algae is also sticky, and because it takes root in crevices, it can cling to and clog your filter. Of course, a clogged filter is inefficient and will only cause more problems in your pool water as it cannot circulate properly. 
  • Erosion and Staining – Algae can alter your pool’s pH level, resulting in scaling and calcium deposits. Eventually, this can cause concrete and fiberglass to erode, cause discoloration, or stain. Damaged equipment is one of those hidden pool costs that you can avoid with thorough algae treatment. 
  • Slips and Falls – Algae in pool water makes surfaces slimy. It has no problem growing on steps, ladders, and the pool walls and floor, making it slippery and potentially dangerous. 

What To Do in Order To Kill Algae

1. Brush Your Pool Walls and Floor

Scrubbing the pool walls will remove algae and allow the chlorine to do its job more effectively and kill any remaining bacteria or algae. Use a sturdy pole with a stiff pool brush to thoroughly scrub the most challenging spots first. The water will become cloudy, so tackling the worst areas first will help you miss less. For concrete or gunite pools, use a stainless steel bristle brush or a nylon bristle pool brush. During brushing, some of the loosened algae will settle to the pool floor, so the next step is to bring out the vacuum.

2. Vacuum Your Pool

It is best to vacuum your pool manually for a thorough cleaning. Use your filter’s waste setting – this lets the contaminated water skip the filter and not recirculate throughout the pool. While you should clean the entire pool, you will certainly want to focus on the areas with noticeable algae. Finally, refill your pool to maintain the correct water levels. 

3. Test the Water

Use your pool test kit to test your water’s pH and alkalinity. It is imperative to balance the water chemistry first so that when you disinfect the water, it will be more effective at killing germs. 

4. Use Shock

Disinfecting your pool is imperative to ward against germs and bacteria to keep your pool water safe and healthy. Chlorine kills most germs within minutes and is typically the best option to address algae and bacteria. 

Shocking your pool is essentially super-chlorinating it. It will raise the free chlorine levels in your water. The more intense your pool algae problem, the more shock you will use. Always follow the package’s instructions in order to use the correct amount for your pool size. Then, depending on the type of algae present, you will need to multiply the dose: 

Green Algae – double dose

Yellow/Dark Green Algae – triple dose

Black Algae – quadruple dose 

It is best to shock your pool in the evening. Or otherwise, the sun will eat up your chlorine too quickly. Leave your filter on for at least eight hours to allow the shock to circulate. If you still have algae in the pool, repeat the brushing and shocking steps of the algae treatment cycle. 

Pro Tip: Leave your cleaning equipment in the pool’s shallow end so the tools will get sanitized during the shock treatment. 

5. Filter the Algae

In the morning, you will see cloudy blue water. This is because the dead algae now need to be filtered out. This means running your filter for eight hours or until the water clears up again. 

6. Test the Water Again 

When your pool looks clean, it is time to test your pool water’s chemical levels again. You want the chemical levels balanced and the chlorine at a normal level. Continue to adjust your pH, alkalinity, and chlorine until everything balances correctly. This is also an excellent time to do more thorough testing, such as calcium hardness and cyanuric acid, since you have removed and replaced water. Again, it’s imperative to ensure everything is balanced before anyone gets into the pool. 

7. Clean the Filter

With the significant amount of contaminated water that your filter processed, it is crucial to do a thorough cleaning of the filter. You do not want microscopic algae spores reentering the pool and starting the algae growth process again. Clean the filter cartridges, or replace them entirely. For D.E. filters or sand filters, do a backwash. 

How Can Pool Equipment Prevent Algae? 

Correct pool maintenance is essential for preventing algae. Since prevention is always easier than treating an existing problem, you must practice good chemical management. If your chemical levels are regularly monitored and adjusted as necessary, it will help you prevent various issues. However, pool equipment also plays a significant role in algae prevention. Running your pump correctly is essential for circulating water.

Cleaning filter cartridges is necessary to reduce the chances of reintroducing contaminated water. It’s also vital to keep your pool clean from debris. As algae spores can be introduced to your water quickly from leaves or other organic matter, getting them out as soon as possible is essential. The tools you use to rake and skim your pool are important because flimsy tools make cleaning tasks more difficult. If a pool owner decides to leave a little clump of leaves until next time because they are frustrated by their cleaning tools, they are taking a risk with their pool water. 

Knowing how to deal with pool algae is a critical part of pool maintenance

Pool algae can be a severe problem, so taking the time to vacuum properly, scrub your pool clean, and check your pool’s chemistry is imperative. Fortunately, correctly maintaining your pool is an excellent preventative measure. With our pool rake special, you will have a pool rake that does the job you need. You do not have to worry about an ineffective, flimsy tool that makes your job harder because the lifetime guarantee means you never have to worry about buying another pool rake. We know they will help you quickly and efficiently clean your pool as part of routine maintenance, preventing further issues with chemical levels, algae, or other problems. Contact ProTuff today if you have questions about pool cleaning and maintenance. ProTuff products are built to last, and we stand behind their quality. 

Disclaimer: Pool ownership and maintenance is very complicated, and we know every situation is unique. While we’ve done our best to cover the best practices here, we encourage you to reach out to ProTuff directly at with any specific questions you may have.

7 Things You Must Know About Killing Pool Algae
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