Why Does My Pool Get Algae?

If you are a pool owner, you are probably familiar with algae. They are those annoying green seaweed-looking things that are not actually plants. Algae can be very toxic to humans, and they should be dealt with right away.

Why does my pool get algae? There are many possible causes why algae have formed in your pool. Some might be attributed to improper pool maintenance and neglect. Other causes may be due to external factors like the weather.

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This article will discuss what algae are, what causes algae, and why they are harmful. There will also be some prevention tips included in the end.

What Is Algae?

Algae are aquatic organisms that cannot be identified as plants, animals, or even fungi. They are usually green or brown and pop up in water bodies like ponds, rivers, or lakes. Algae are not specific to one area or region, and they can even be found in the snow. Human-made swimming pools are not exempt from this.

Aside from looking a bit gross, algae can also be detrimental to people’s health. They make the pool water cloudy, seep up the chlorine, and produce toxins.

Large algae blooms may lower oxygen levels in the water and release harmful chemicals. It is best if you, your family, and your pets do not swim in a pool filled with algae.

Causes Of Algae

The most probable cause of algae in swimming pools is neglect or poor maintenance. If you decide to own a pool, you have to manage its upkeep. You must do routine checks to ensure the pool system is running smoothly and that there are no issues.

Some reasons why algae have formed could be because of poor water pH balance, poor circulation, poor filtration, and poor sanitation. Perhaps you are not paying attention to the chlorine levels or alkalinity of the pool’s water.

There might be clogging or problems with the pool’s filtration system. These things, combined with the extreme summer heat, will invite hoards of algae into your pool.

The algae in your pool may not even be your fault. Sometimes strong winds bring algae spores, or your guests might bring them when they swim in your pool. It could also be because the pool cleaning tools became contaminated somehow. 

Prevention Of Algae

The best way to prevent algae in your pool is to do regular maintenance and cleaning. Make sure the water’s balance, circulation, filtration, and sanitation are working in the best condition.

For the water balance, keep the pH at 7.2, and watch out for the calcium levels as well. Clean and unclog every part of the filtration system, including the pump, filter, drains, and skimmers.

If algae flourished in your pool, the only thing to do now is to kill them. You can use chemical treatments like potassium tetraborate, or algaecides and algaestats. 


The reason your pool is filled with algae could be because you have not been sanitizing your pool correctly. Algae also thrive in hot temperatures, which is why they are more likely to appear on very hot summer days.

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