Why is My Swimming Pool Green?

If you’re itching to take a dip in your pool but scared because it looks like a lake, don’t fret. There are some easy fixes to make your pool sparkle again.

There are several reasons why your pool water might be looking a bit greener than usual this summer. Let’s look at the causes and what you can do about them.

Why Is My Swimming Pool Green?

Having a green pool is not something that you want to have, but it can happen for many different reasons. Your pool’s water may be turning green for several reasons. The most common reasons include:

  • Pesticides or other chemicals have been added to your pool (or the water supply).
  • A sand filter may contain organics, which can cause algae growth if your pool has a sand filter. Sand filters remove the organics from the water before sending it back into your pool. If these organics aren’t removed properly, they can cause algae growth.
  • Turbidity in your pool water is caused by suspended particles in your pool’s water. These particles can come from anywhere — dust and dirt can land on your pool’s surface, or you might even see leaves or pine needles falling into the water during a storm (particularly if your filter isn’t running).
  • Chlorine kills algae. However, if there is too much chlorine in the water, it will kill everything else as well. Ensure enough chlorine is added to keep algae at bay (1-3 parts per million).

10 Ways to Fix a Green Pool Fast

If you have a green pool, it’s time to act fast. The longer you leave it, the more likely your pool will turn iridescent green and be impossible to fix. There are several ways to quickly get rid of algae in your pool:

Vacuum Your Pool

The best way to get rid of green water is to vacuum it out. You can use a handheld vacuum or an electric one if you have an in-ground pool. 

Vacuuming will remove all of the debris from the surface of your water, which is what causes it to turn green in the first place. 

How to Vacuum a Pool

It also helps eliminate any algae that may be growing on the bottom of your pool, making it easier for chemicals to work their way down into the water and kill off any remaining algae spores at the bottom of your pool.

Shock the Pool

Shock the water with chlorine or bromine shock. This will kill the algae and other contaminants that cause the green color, but it can also shock swimmers who may not be using goggles or nose plugs. 

Clean Up Leaves and Debris

Clean up leaves, debris, and dirt from around your pool as soon as possible to prevent debris from falling into the water while you’re trying to get rid of algae in your pool. 

You can use a leaf rake or leaf skimmer to remove leaves before they fall into the pool or clean up after storms when leaves blow in from nearby trees or bushes onto your property.

Add Algaecide to Your Pool

Add algaecide tablets or granules to kill all types of algae in your swimming pool water by breaking down their cell walls so they sink to the bottom of your swimming pool, where they can’t cause any damage. 

This is especially useful for blackwater pools where sunlight doesn’t penetrate.

Scrub the Surface

If you have a lot of algae on the surface of your pool, a garden hose sprayer or telescoping pole with a scrubbing pad can help remove it. 

The idea is to loosen the algae so the chlorine can kill it more effectively. Be sure to spray off all pool surfaces after cleaning them with chlorine.

Lowering the Water Level

If your pool is too deep, lowering its depth will reduce sunlight penetration and slow down algae growth. 

This may be helpful if your water is already clear, but if you wait too long before treating your pool with chlorine, lowering the depth won’t help much with clearing up green water.

Adjust the pH Level

The pH level is a measure of acidity. Most pools should be in the 7.2-7.6 range, with 7 being neutral. If your pH is too high or too low, it can cause stains and make it harder for chlorine to do its job of killing bacteria.

Clean the Filter

Make sure that your filter is clean and working properly by performing regular maintenance on it. If you have an automatic cleaner, check to see if that is working properly as well. If not, then clean or replace it as needed.

Check for Leaks

An obvious leak in your pool can cause algae growth or even mold if it stays wet long enough. 

Ensure that all your filters, skimmers, drains, and returns are working properly and that no leaks are present before adding chemicals or performing any other cleaning procedures.

Leave the Filter Running

If you have a sand filter, turn it on at full speed and leave it running for 24 hours. If you have an automatic cleaner, turn that on as well. This will help clear out some of the algae from the bottom of your pool.

How Can I Prevent My Pool From Turning Green Again in the Future?

The best way to prevent your pool from turning green again is to keep it clean. If you have been neglecting your pool, your first step should be to get back on a regular cleaning schedule and follow it religiously. 

The more often you clean your pool, the less likely you will develop algae issues in the future.

Algae will also grow if there is too much organic material in the water or if sunlight penetrates into the water through cracks or leaks. 

If you have cracks in your pool or if it has been poorly repaired, fixing these issues will help reduce the amount of sunlight that penetrates into the water and encourage algae growth.

You should also add a chlorine stabilizer to your pool when using chlorine-based sanitizers such as chlorine tablets or liquid chlorine. 

This prevents any chlorine that escapes from reacting with organic material in the water and turning into chloramines that are harmful to swimmers’ health and make pools turn green over time.


Q. Can too much chlorine make the pool green?

A. Yes. Too much chlorine in the pool can make it turn green.

Chlorine is a powerful disinfectant that kills bacteria and other contaminants in pools, so it’s important to keep your pool’s chlorine level at a healthy dose. But too much chlorine can cause red eyes and itching skin and make your pool turn green.

Q.How long does it take to clear a green pool?

A.It takes 3-4 days to clear a green pool. The process can be sped up by using a pool brush and vacuum, which will help remove the excess algae and other debris causing your pool to turn green.

Q.Is it safe to swim in a green pool?

A.No. Green pools are not safe to swim in. Green pools can cause bacterial infections on your skin and can also be dangerous to your health if you drink them. It’s best to stay out of a green pool altogether.

Q.Why did my pool turn green overnight?

A.If your pool has been treated with chlorine, it may be turning green due to an imbalance in the pH of your water. The pH levels in pools should be between 7.2 and 7.8, but if you notice your water is too acidic or too alkaline, it could cause a change in the color of your pool water.

Q.Will baking soda clear a green pool?

A.Baking soda is alkaline, which can help clear up a green pool by neutralizing the acidic pool water. However, baking soda is not recommended for pools that have algae; it can actually make the problem worse because it will help the algae grow.

Q.Why won’t my green pool clear up?

A.The problem is that if the water is too cold for the filter to work properly, it cannot remove all of the chlorine from the water. The chlorine is what’s causing the green coloration in your pool.

Q.Can you over shock a green pool?

A.Yes, you can over shock a green pool. You’ll want to start with a shock one step up from the recommended number on your pool chemical chart. The shock will need to be followed by a water change and then another dose of chlorine.


It’s important to remember that your pool’s condition is directly related to how much water you put in and how much chlorine you add. This means that, while you may want to leave things alone and enjoy a clean pool, there are specific ways to maintain this balance. Call a local pool company for a consultation and quotes on cleaning and maintenance prices.

Hopefully, the above steps will help reduce the chances of your swimming pool being green soon. That way, you can continue having fun without worrying about your pool’s state.

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