Why is my swimming pool green?

Why is my swimming pool green

Swimming pools are a fantastic source of summertime entertainment, but finding out the water has turned an unattractive shade of green can quickly ruin a day at the pool. Even though a green pool might not always be risky, swimmers may find it off-putting and unsightly. What can you do to fix your swimming pool’s green color and why is it green?
We’ll examine the most frequent reasons why a pool turns green in this article, along with fixes. All summer long, you can take advantage of crystal-clear water by keeping up with pool maintenance.

Causes of a Green Swimming Pool

Many things can contribute to a swimming pool turning green. Let’s examine each one in more detail.

Algae Growth

Algae growth is one of the most typical causes of a green pool. Microorganisms called algae can flourish in swimming pool water, especially if the chemical balance is off or the pool is not kept up with. Algae can grow on the pool’s walls, floor, and surface and can be green, black, or even pink in color. Although algae are not always dangerous to swimmers, they can cause the water to look dirty and feel slippery.

Lack of Proper Filtration and Circulation

A swimming pool needs to have adequate filtration and circulation in order to stay clean. The circulation system helps to distribute the chemicals and keep the water moving while the filtration system helps to remove dirt, debris, and bacteria from the water. The accumulation of contaminants that can result in the water turning green can be caused by a malfunctioning filtration system or inadequate water circulation.

Incorrect Chemical Balance

In order to keep the water in a swimming pool clean and clear, the proper chemical balance must be maintained. Algae can flourish in the ideal environment if the pH level is either too high or too low. Additionally, a green pool may result from improperly balanced chlorine levels.

Lack of Proper Cleaning and Maintenance

Maintaining a swimming pool on a regular basis is crucial for keeping it clear and clean. The pool should be brushed, the surface should be skimmed, and the chemical levels should be checked and adjusted. A pool can easily turn green and cloudy if it is not regularly cleaned and maintained.

Diagnosing the Cause of a Green Pool

Now that you’ve established that your pool is green, what is the reason behind it? To diagnose the issue, you can follow a few steps.

Testing the Chemical Balance of the Pool Water

Checking the chemical balance of the pool water should be one of your first steps. To do this, you can buy test strips or a testing kit, or you can take a water sample to a pool expert for analysis. The chlorine concentrations should range from 1 to 3 ppm, and the pH value should be between 7.2 and 7.8. (parts per million). Algae can thrive in the ideal environment if the pH is either too high or too low or if the chlorine levels are off.

Inspecting the Filtration and Circulation Systems

The filtration and circulation systems should then be checked to ensure proper operation. Look for any leaks in the circulation system and make sure the filter is clean and not blocked. The effectiveness of the filtration system may be decreased if the filter is dirty or clogged, which may cause contaminants to accumulate in the water.

Examining the Pool Surfaces and Surroundings for Signs of Algae Growth

Examining the pool surfaces and surroundings for indications of algae growth is crucial in addition to testing the chemical balance, filtration, and circulation systems. Algae can show up as green or black spots, a slimy film on the pool’s walls and floor, or both. Your pool is probably turning green because of algae if you notice any of these symptoms.

Solutions for a Green Pool

It’s time to take action to fix your green pool now that you know what’s causing it. You can try the following remedies:

Shock Treatment to Kill Algae and Bacteria

If algae are the problem, a shock treatment may work well to eliminate it. A shock treatment involves flooding the pool with chlorine, which can eradicate the bacteria and algae. When using a shock treatment, it’s crucial to adhere to the manufacturer’s recommendations and allow enough time before returning to the pool.

Properly Balancing the Pool Chemicals

A pool’s improper chemical balance can foster the ideal environment for the growth of algae. The algae growth can be halted by carefully balancing the chemicals in the pool. When adding chemicals to the pool, be sure to follow the manufacturer’s instructions. You should also test the water frequently to make sure the chemical levels are appropriate.

Cleaning and Replacing the Pool Filter

A dirty or clogged pool filter can make the filtration system less effective, which causes contaminants to accumulate in the water. Maintaining a clean, clear water supply can be achieved by routinely cleaning or replacing the filter.

Increasing Circulation and Filtration

Increasing circulation and filtration can help to keep the water clean and clear in addition to cleaning and replacing the filter. Longer periods of pump and filter operation can aid in circulating the water and removing impurities.

Properly Maintaining and Cleaning the Pool on a Regular Basis

A green pool can be avoided with proper upkeep and cleaning. This entails brushing the pool, checking and adjusting the chemical levels, and skimming the surface. All summer long, you can keep your pool clear and clean by sticking to a regular maintenance schedule.


Although a green swimming pool is a common issue, it is one that can be quickly resolved with the proper method. All summer long, you can take advantage of crystal clear water by being aware of the most typical causes of a green pool and taking action to address them. There are ways to restore your pool to its former splendor, whether it’s through a shock treatment to kill algae, properly balancing the pool chemicals, or boosting circulation and filtration. You can stop the issue from happening again in the future by keeping up with a regular cleaning and maintenance schedule for your pool.