How to Get Rid of Algae in Pool

By Greg Jarvis | Last Updated: September 7, 2022

The most common problems of swimming pool owners are having floating algae or green water. Algae can grow freely in the water. It can cling on the pool surface most of the time in patches. These algae are harmless, but they can cause inconvenience and make the pool look ugly.

Below are methods on how you can get rid of algae in your pool. Once you get rid of the algae, you must maintain regular pool maintenance to prevent them from returning.

Methods on Getting Rid of Algae in Pool

The best method of eliminating the algae in the pool is by using Chlorine. Other methods listed below are faster, but it might not solve the underlying sanitation issues. Some methods are also expensive and may have undesirable side effects.

Use Chlorine to kill the algae

If you notice your pool water is green or has visible algae clumps, it only means that the pool does not have enough Chlorine. Adding Chlorine can kill the algae and keep your water into its cleanest condition. It can last within one to three days, but if your pool has a poor condition, it may take a week to clean it.

Use Brush to Remove Algae

Brush the walls and floor vigorously to remove all the algae. This will lessen the time it takes to eliminate and clear the algae bloom. Focus on the steps, ladders, and other crannies and nooks where algae usually gather.

Choose the brush that is compatible with your pool. Nylon brushes can be used on vinyl, while steel brushes are recommended on concrete.

Use Chemicals to Remove Algae

In using chemicals, you need to be very careful as these substances are quite dangerous if not handled well. Read the safety information printed on the label. Here are safety standards that you usually find on all pool chemical labels.

In cleaning, use durable gloves, wear the right clothing to cover your skin, and have eye protection.

After using the chemicals, wash your hands and check your clothes if there are chemicals that adhere to them.

Do not inhale the chemicals. Be very careful when handly the chemicals during windy weather.

Dilute the chemicals in water, not water to chemicals. Never return wet scoops in the container.

Keep the chemicals in tightly sealed, fireproof containers and away from the children. Make sure that the chemicals are stored on different shelves as they might explode when they touch another pool chemical.

Adjusting the Pool pH

To measure the pool’s pH use a pH test kit designed for swimming pools. If the water’s pH is above 7.6, which is common if the algae bloom – you can add a pH reducer to your pool like sodium bisulfate depending on the label instructions. Your target pH is between 7.2 and 7.6 to boost the action of your Chlorine and minimize the growth of the algae. After several hours of treating the water, test the pool again.

Using tablets or droppers as test kits are more accurate as compared to paper test strips

If the pH levels return to normal, however, the total alkalinity is over 120 ppm. Check the label of the pH reducer on how to lower the alkalinity between 80 and 120 ppm.

Clean the Filter

If your pool has a D.E. filter, set it to backwash. But, if you have a cartridge filter, take it out and clean the cartridge using a hose with high pressure, then wash it using liquid Chlorine or muriatic acid if needed. If you failed to clean the filter thoroughly, dead algae get to block the filter.

Improve Water Circulation

If you see small clumps of algae in the pool but do not spread in the water, there might be areas where water is stagnant. Make sure that your water jets are functioning correctly. The jets should be pointing into the water at an angle so the water will move in a spiral pattern.

Use Flocculant to Gather the Algae

A coagulant or flocculant gathers the algae together, which makes it easy to vacuum living algae. It may be a daunting task, but your pool will be clear after doing it. This method of getting algae is the quickest way to get your pool free from algae, but it does not mean that it is safe to swim.

There could be some bacteria and viruses in the water. After removing the algae, you can do the chlorine shock treatment afterward to sanitize the water in the pool. You can only swim in the pool if the chlorine and pH levels are a standard value.

Treat the Pool with Algaecide

If there is one chemical that could effectively eliminate the algae, it’s the algaecide. However, the adverse effects and the cost is not worth it. If you are considering this option, there are factors that you need to consider.

If you choose the wrong algaecide product, you might not succeed in eliminating the algae, particularly if you have black algae. You can seek help from the pool store employee or look for a product with 30% plus active components.

There could be some cheap algaecides, but it can cause the water to foam, and many people are not comfortable with it.

If you can afford the price, it is best to choose copper-based algaecides. However, it might stain your pool walls.

After adding the algaecide, you have to wait for 24 hours before putting in other chemicals.


It does not matter what the type is and the number of algae invading your pool. You can get rid of them quickly by applying some of the techniques mentioned above.

Vacuuming the pool twice is not necessary if there is only a small amount of algae as you can easily remove them.

However, if black algae are invading the pool, you may need to shock more than four times, which means that you do some of the techniques mentioned above.

Getting rid of algae is not an easy task. That is why it is best to maintain your pool correctly and make sure you clean it regularly. If you have questions about getting rid of algae in the pool, feel free to comment below.

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