Last Updated on July 26, 2022


A green pool is a terrible thing and you will want to clear this as soon as possible.  There are a number of issues that could cause this including the filter system and the improper use of chemicals.  Fortunately, there are a number of steps that you can take which should help you clear your pool in 5 days or less.

Test the Water

The first step to clearing your pool will be to test the water.  You will need to use a chemical test kit which can be bought from any pool supply store.  The test kit will test the pH levels and chlorine levels in your pool which will help you determine the extent of your problem.  If the chlorine level is below 1ppm, this will be the cause of your green pool. 

Balance the Pool Chemistry

After testing the pool water, you will have a better idea of the chemistry balance.  This will be the pH level of your pool and you need to either add an acid or alkaline to it.  The pH level that you want to get your pool water to is around 7.8. 

It is important to note that this is a pH level that is higher than you would want when swimming.  However, when you are trying to clear the algae in your pool, this is ideal.  After adding the chemicals to your pool, you need to turn the pump on.

The pump will help to circulate the chemicals through the water.  The chemicals that you need to add to your pool can be purchased from your pool supply store.  They will generally tell you if they are going to increase or decrease your pH level.

Check the Filter

It is important to note that you should be checking the filter before you start adding any chemicals to your pool.  The filter will need to be cleaned and you have to remove any debris that could be clogging it.  Common debris will include leaves and sticks which have fallen into the pool. 

If you need to, you should backwash the filter to ensure that it is working correctly.  Only turn the pump on after adding chemicals if the filter is working correctly.  If the filter does not work correctly, it will need to be repaired before you do anything else.

Clean the Sides and Bottom of the Pool

The bottom of your pool is generally going to be fairly hard to see when it is green.  However, you do need to take the time to clean the bottom and the sides.  To do this, you should use an algae pool brush.  Again, it is recommended that you do this before you start adding chemicals to your pool water. 

This is an important step because algae hold onto the surfaces in your pool.  When you scrub the bottom and sides of the pool, you will be breaking up the algae.  This will allow the chemicals to work faster. 

Use a Shock Treatment

If you have a lot of algae in your pool, you need to look at a shock treatment.  Shock treatments will have high levels of chlorine in them which is ideal for killing the algae and sanitizing the pool.  To handle both bacteria and algae, you need to use a shock treatment that is 70% chlorine.

Of course, it is important to note that you need to be very careful when using a shock treatment.  The high chlorine content can be harmful to humans and animals.  You should always wear protective clothing such as gloves when you are working with shock treatments.

When you add the treatment to your pool, you may notice that the water becomes cloudy.  This will clear up as your water runs through the pump and the shock treatment is dispersed.  If you have a large number of algae in your pool, you may have to complete more than one shock treatment. 

Clean the Filter Regularly

As the shock treatment kills the algae, you need to regularly remove and clean your filter.  This is due to the fact that a buildup of dead algae will form in the filter which could clog it.  Cleaning the filter with a filter cleaner is important to kill any algae or bacteria which are clinging to the filter. 

Vacuum the Dead Algae and Debris

One of the final steps in clearing your pool will be to vacuum the debris and dead algae.  To do this, you will need to first clean the sides and bottom of the pool again.  After doing this, you will need to vacuum the dead algae and other debris to ensure that your pool is clean.

Run the Filter and Monitor the Water

At this point, your pool will be looking quite clear and you might think it is safe to swim.  This is not recommended as you should run the filter and monitor the pool for a few days first.  This monitoring will allow you to see if the algae returns after the filter start to run.

If the alga does start to come back, you will need to shock the pool again.  This will kill the remaining algae and stop it from coming back.

Check the Chemical Levels

If your pool remains clear, you will need to check the chemical levels again before you go swimming.  It is important that you take the time to do this as you do not want to jump into a pool that is too acidic.  Your pool testing kit will generally provide guidance on what a good pH level will be for swimming.  If your water levels do not match this, you will need to treat the pool to raise or lower the levels.


It is possible to clear a green pool in 5 days or less.  The key is to know what steps you should be taking and the order that you should complete them in.  While you are doing this, you need to remember your safety around the chemicals.