How to Get Rid of Algae in Pool

There are some pool issues you can almost be sure you will have to deal with at some point, no matter how keen you are with pool maintenance.

One such problem is algae, and it is also one of those that pool owners hate most as it can render the pool unusable and cause other issues such as clogged filters.

That said, the best you can do is know how to deal with the problem when it occurs and how to prevent or at least reduce the likelihood of getting algae. But first, you need to understand what pool algae is, why it forms in your pool, and the different types.

What is Pool Algae? 

Pool algae is simply a plant-like organism that grows over the pool water. These photosynthetic organisms use the sun, water, and carbon dioxide to make their food, and pool water provides adequate amounts of all three, meaning they can multiply super-fast.

Although pool algae do not pose any serious health concern, they provide a conducive habitat for harmful bacteria that can be dangerous to the swimmers and pets like E. coli.

Also, algae make the pool look unsightly and will often also clog your filtration system and damage pool fixtures.

In most cases, it is not always easy to point out the specific algae source since most types are airborne organisms all around the pool environment.

However, in many cases, algae grow due to out of balance pool chemistry, inefficient filtration system, and inadequate pool water circulation.

Types of Pool Algae

Algae is a large and diverse family of eukaryotic microorganisms, meaning you can get it in several forms and types. However, as a pool owner, there are four main types you are likely to encounter: green, mustard/yellow, black and pink algae.

1. Green Algae

Green algae are the most common type and what almost every pool owner will need to deal with at some point. Also, this algae type is the quickest and easiest to remove as it is not as stubborn as the other types.

When you have green algae in the pool, you will see it floating over the water or clinging to the pool walls.

Green algae often form when your water pH is too high, and your sanitation and filtration systems are not working well. Also, swimmers and pool toys can introduce it to the pool.

2. Mustard/Yellow Algae

Mustard or yellow algae is a type that thrives in shaded areas of the pool. It is also quite common and comes second only to green algae in the list of the types you are most likely to encounter.

The algae are easy to mistake for other things like pollen or sand given their appearance, so some pool owners often miss it until it becomes a severe problem.

Given that yellow algae are chlorine-resistant, it is harder to eliminate than green algae. However, a good dose of pool shock and thorough scrubbing of the pool often does the trick.

3. Black Algae

Technically, black algae are not algae as they are a type of cyanobacteria. It is one of the most complicated types to eliminate because it makes its own food, which allows it to multiply faster, and tends to get deep into the concrete pool surfaces.

In many instances, it is the swimmers that introduce the black algae to your pool. If someone was swimming in natural bodies of water like lakes or the ocean and uses the same swimsuit in your pool without proper sanitization, there is a greater risk of getting black algae.

A high dose of a strong pool shock, a potent algaecide, and a good pool brush are crucial when dealing with this algae type.

4. Pink Algae

Pink algae or pink slime is also a bacteria type, and it often grows in PVC pipes and the shaded areas of the pool, such as cracks and corners.

Pink algae manifest as a slimy layer over the water and pool fixtures. There is no one specific cause, but it is often a result of improper pool water maintenance and circulation. It also does not pose any significant health risk, but it can clog your filters and is unsightly.

Like black algae, it is also chlorine-resistant, but a good dose of highly concentrated pool shock should kill it.

How to Get Rid of Algae in My Pool Fast

What You Need

• Pool brush and pole
• Water test kit
• Pool shock
• Algaecide
• Safety gear

Step by Step Directions

Step 1: Vacuum Your Pool

The first step when dealing with algae is to eliminate all the algae that you can see floating in the water and around the pool fixtures.

Here you will need a good vacuum that can suck out the algae. A manual vacuum is the best as the robotic pool cleaners do not work well for cleaning algae. 

With a manual vacuum cleaner, you can remove the floating algae without pushing it through the filter, which would make the job harder for you.

Step 2: Test Pool Chemistry

Once you vacuum off the loose algae, the next step is to test your pool chemistry. Keep in mind that water chemistry that is not in balance provides a perfect habitat for algae to grow.

You need to keep track of essential parameters like chlorine, pH, and alkalinity to ensure optimal levels.

It is vital to ensure that you use an accurate and reliable pool water test kit like the LaMotte 2056 ColorQ Pro 7 Digital Pool Water Test Kit. Also, remember to add a stabilizer if you need to increase the chlorine levels, as this prevents quick deterioration.

Step 3: Clean Your Filters

With the pool chemistry balance, the next step is to clean your filters. Remember that if you have algae in your pool, the chances are you also have some in the filters, and so you need to make sure the filter are clean before going to the other steps.

Cleaning your filter should be an easy job and how you do it largely depends on the type. Backwashing is enough for those who use a sand filter, but you need a filter cleaner and have to hose down the filter cartridge for others.

Step 4: Brush and Scrub the Pool

The next step is brushing and scrubbing the pool surfaces to remove the algae clinging on that vacuum could not eliminate.

Here you will need to spare enough time for scrubbing and make sure you choose the right brush for your pool. The Poolmaster 2018318-Inch Aluminum-Back Swimming Pool Algae Brush is a perfect example of a firm pool brush with excellent bristles that scrub all algae types.

Step 5: Shock Your Pool

Once you give the pool surfaces a thorough scrub, you will also need to shock the pool water as this will kill the algae and help you get rid of other contaminants in the water.

Calcium hypochlorite is the best pool shock when dealing with algae as it can contain up to 80% available chlorine making it more effective against contaminants.

Also, make sure you add enough of it to your pool water, and in most cases, at least 3 pounds of shock will be enough for every 10,000 gallons of water.

Additionally, make sure you shock your pool at dusk or even night to ensure the sun does not break down the chlorine before it can kill the algae. Pool shock will require anything from 12 to 24 hours to do the job, so you should not use the pool within that period.

Step 6: Add Algaecide

After giving the pool shock enough time to work, you also need to add some algaecide. The shock will kill most, if not all, the algae, but you need algaecide to prevent future blooms.

Also, make sure you give your algaecide at least 24 hours to circulate in the pool properly. Running the pump can also be very useful here as it speeds up circulation.

Step 7: Brush and Vacuum Pool

The next step is to give the pool another thorough scrub. A second scrub and vacuuming ensures you do not miss any spots.

Step 8: Run and Clean the Filter

After brushing and vacuuming, you need to run your filtration system to allow the filter to capture any contaminants you brush off the surfaces.

Run the filtration for at least 8 hours but the longer, the better. When satisfied you have done enough filtration, the next step should be to give your filter a thorough cleaning.

Step 9: Test and Balance the Water

The last step should always be to test your pool chemistry again and balance it if necessary to get the pool ready for use.

How to Prevent Algae in My Pool

1. Keep checking your pool chemistry regularly and ensure you balance anything that is not at the optimal level. The pH, alkalinity, calcium hardness and chlorine levels are the most crucial parameter to check.

2. Ensure that the water filtration system and pump are always working correctly and that your filter is clean.

3. Remember to shock your pool after heavy rain or storms and periods of heavy usage and at least once a week during regular use.

4. Add algaecides to your pool often, as they are very useful for preventing the formation of algae.

5. Make sure you clean all the pool toys, accessories like ladders and slides and your pool cleaning equipment regularly.

Bottom Line

Algae is one of the most annoying problems you can encounter in your pool as it leaves it looking unsightly.

The good news is that it is pretty easy to remove, and you only need to know what it is, the different types you can encounter, and the steps to follow.

It is always much better to prevent algae formation by following a proper pool maintenance routine. The routine should entail testing and balancing the chemistry, regular shocking, cleaning filters often and using algaecides.