Help My Pool is Green, what can I do?

Do you have a problem with a green pool? This is a result of an algae bloom and bacteria in the water leaving an unsafe pool for swimming. This growth can be due to any of the following reasons.

Improper Filtration

The filter system is responsible for removing debris including algae from the pool. There are two filter types used for domestic swimming pools – media filters and cartridge filters

Various types of media can be used in a filter the two most common are sand and glass media. In a sand filter system, the water is pumped through the sand, the sand captures the debris & algae allowing the filtered water to return to the pool, the sand should be changed every 4-5 years.

Glass filters work as above but with an additional benefit that it is able to attract and separate more minute particles, the glass should be replaced every 8-10 years, depending on the type & manufactures recommendations.

In a cartridge filter, corrugated paper or polyester cloth is used to separate the pollutants.

If the filter becomes clogged with debris and or contaminants it will not work properly, which may allow algae to flourish, resulting in a green pool.

Incorrect pH Balance

On a pH scale, a healthy pool has a range between 7.2 and 7.8.

Higher pH levels indicate that chlorine will be less effective in the pool. This will allow the growth of algae and bacteria, causing the water to change colour.

A lower pH level will turn the pool acidic, corroding metals and plastic that come in contact with the water.


Phosphates are food for algae. ... High phosphate levels, when left untreated, will generally result in higher chlorine demand and can lead to algae blooms in your pool. Phosphates can enter your pool from rain or run off, pets and sun screen lotions. Our shop will test for the presence of phosphates and provide you with ways to remove them.

Returning the Water Back to Normal

There is no magic wand or one stop wonder product for this job, it's a process and one that often needs multiple chemicals and visits.

Firstly, check that the filter is working correctly. Then make sure that it is running for an adequate amount of time, for example – 2 hours per day in winter and 8 hours in summer. If the filter is not performing as expected, call for help.

Secondly, if the discoloration is caused due to a lack of chlorine or water imbalance, then you need to bring a sample of your pool water in for testing. About 1 cup of water is enough for the test, but make sure it is less than an hour old when you submit it.

Remember to not collect water from the top surface layer of the pool. Instead, take it from about an elbow’s length down, and away from the jets. Our shop will check the water balance and give you advice on which chemicals are required to rebalance and help remove the algae bloom from the pool.

In all likelihood, you will have to treat the pool with large quantities of algaecide and chlorine. Within 24 hours of adding these chemicals to the water, the microbes should effectively be killed off, providing you follow our instructions. You can also use a phosphate remover to clean out any phosphorous present in the water.

But if the swimming pool remains green even after the chemical treatment, you need to call in a professional pool expert to help resolve the issue.

Do you need help right now?

Having a green pool is a problem that no one wants to have, so the best thing is to call in Poolcare on 07 575 8471 and we can assist in returning your green pool back to a healthy sparkling pool as soon as possible.