How to fix cloudy pool water: reasons, solutions & trouble shooting

cloudy pool water

If you own a pool then chances are you’ve had to deal with cloudy pool water. This can not only be a challenging issue to solve, but can also be very frustrating. There are many different contributing factors as to why your pool may be cloudy, making it difficult to fix. Today we’ll be going over the various reasons, and options to get that pool water of yours crystal clear again.

But before we get into the solutions, let’s dive into the reasons why your pool water maybe cloudy.

  • Poor filtration
  • Low Chlorine
  • Chemical imbalance
  • contamination

Poor Filtration

If you’ve taken your filter out and thought wow that could be causing the problem, then a good clean could be in order. Dirty filters can lead to all kinds of problems in your pool, so you want to check your filter regularly and give it a decent clean three times a year or more depending on usage.

If your filter has a buildup of debris, it’s time to backwash your sand or D.E filter. Make sure you give your D.E filter grids or cartridge filter a good scrub as well.

pool cloudy after shock

Replace your pool filter media

It’s a good idea to give your filter a good once over and identify if there is any damage, or wear and tear on any parts. If your filter media has any damage or is simply worn out it won’t be able to capture sediment or debris which could be contaminating your water.

Taking this into account a cartridge replacement or sand replacement in your sand filter could be required, or a part may need to be replaced. Cartridges usually have a life span of one to 2 years and sand needs to be replaced every 5 years. If you have a D.E filter add fresh diatomaceous earth powder or replace your D.E grids.

Check your pump & circulation

Without your pump being in good working order your filter cannot do its job, and your pool circulation will certainly be impaired. Make sure all the parts are working smoothly and nothing needs repaired or replaced.

Your pool filter relies on your pump to push water through the filtration system and keep that circulation going. For premium water quality you need to be running your pump for 8 to 12 hours a day minimum. So, if you haven’t been doing so and have cloudy pool water it’s time to crank up that pump!

cloudy pool after shock

Does low chlorine cause a cloudy pool?

Check your chlorine levels in your pool water

Firstly, you will want to test your water using a pool testing kit. These are designed to measure the pools chlorine levels, its alkalinity, calcium hardness and pH levels. Your free Chlorine levels need to stay between 1 to 3 parts per million (ppm). If levels drop below 1 you will need to add more chlorine to your pool.

Check your combined chlorine levels

If your free chlorine levels are lower than your total chlorine reading you can end up with chloramines. Chloramines are a byproduct of chlorine sanitizing which can be irritating and corrosive. Your combined chlorine is the difference between your free chlorine reading and the total chlorine reading. Your combined chlorine should be below 0.5 ppm.

Shock your pool

If your pool needs a free chlorine boost, then a pool shock is a perfect quick way to get that level up. Its best to use a calcium hypochlorite shock, Calcium hypochlorite should be the main ingredient in your pool shock. During peak season you should aim to shock your pool once a week to refresh your sanitizer levels.

Chemical Imbalance

Cloudy pool water

A high pH, calcium hardness and total alkalinity can lead to all kinds of problems with your swimming pool. Bacteria can grow, plus your filtration and circulation system will start to under perform. This could attribute to a cloudy pool, and poor pool water chemistry disables your chlorine function.

1. Test your Total Alkalinity levels

Your alkalinity acts as a stabilizer for your pH levels, so this should be your first stop when balancing your pool. Your alkaline levels need to be 100 parts per million (ppm) to 150 ppm with 125 ppm being your ideal level. If your levels are too high this can cause pH and calcium scaling. To lower your alkalinity levels use muriatic acid or a pH decreaser. To raise alkalinity levels, use an alkalinity increaser or baking soda.

2. Check your pH level

If your pH levels are out this can affect how your chlorine works, and can cause calcium build-up.

The pH of your pool should sit between 7.4 and 7.6, if the levels drop below 7.0 this would indicate that the water is too acidic. Levels above 7.8 mean that the water is too alkaline, A pH adjuster can help to decrease or increase the pH levels. If the pH levels are off this could be leading to cloudiness in your pool.

3. Calcium hardness

High calcium hardness can cause build up and calcium scale on your equipment and inside your plumbing. This is not an easy fix, and can create cloudy pool water.

Unfortunately, the only way to resolve this issue is to partially drain and refresh your pool water. Keep in mind that this well effect your pool chemistry so you will need to test and possibly rebalance your pool chemicals.


why is my pool cloudy

There are a few ways your pool can become contaminated, leading to cloudy pool water. Early-stage algae growth or small debris are two of the main culprits, these are both a pretty easy fix. Also, seasonal changes can have a huge effect on contaminating your pool. Wind, sun, pollen and rainfall have a big part to play in debris and algae growth within your pool.

treat Algae in your pool

If you already have visible algae growth in your pool you will need to get rid of the algae before you begin treatment on your cloudy pool water. To get rid of the algae you will need to skim, brush and vacuum your pool.

Make sure to bypass the filter by using the waste setting while vacuuming. Afterwards you will want to shock your pool. The best way to control algae growth within your pool is prevention, using a good Algaecide will help with algae control.

test, clean & balance your pool after a rainstorm.

Storms and rainfall can dilute the chemicals in your pool water leading to a drop in chlorine levels. Make sure you test and balance your water after any significant weather event and skim, brush and vacuum if needed.

should i use a Pool clarifier?

These are a great quick fix, and work best for mild cloudy pool water. Pool clarifiers work by gathering smaller particles together to create larger ones making them easier to be picked up by your filter they can be used with any filtration system. How powerful your pump and filter are will determine how quickly the clarifier works.


So there you have it, I hope this have given you the info you need to help diagnose your cloudy pool water. There is a lot to take in when it comes to fixing this problem so I sincerely hope this article has helped you get to the bottom of what could be causing this for you.

If you’re having trouble with green pool water, then check out our full troubleshooting guide here.

Happy swimming!

The Morris's

The Morris's

Hey, we're Lana and Cam the creators of this site. We love to spend time together as a family, and time in our pool. We're here to bring you the best info on pool care, pool cleaners, and other great pool related products.

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