How Do You Clear Up a Cloudy Swimming Pool Water?

Our natural instinct as humans is not to jump and swim into a cloudy or foggy water, and our brain has associated murky water with an unsafe environment. And most of the time, we are right. However not always cloudy pool water means a toxic environment. But, when it does, it can be extremely unhealthy to our bodies and a hazardous place to be. In this article, we are going to cover, what exactly causes cloudy pool, how to prevent it from happening, and finally how to fix it.

What Causes Cloudy Pool Water?

Cloudy pool water can happen to any pool owner. While there are many reasons why this can happen, here are the most common ones:

  • Not enough chlorine
  • Clogged filter, filter leak or poor filtering
  • Too much sodium bicarbonate
  • High pH high alkaline or high calcium hardness
  • Chloramines
  • Environmental causes

Below in this article, we take each possible scenario, and we explain in details how to solve it, step by step.

How to Prevent Cloudy Pool Water at first place?

Get a pool cover. This is one of the easiest ways to prevent cloudy pool water, at least to protect your pool from the environment and weather hazards.

Keep your deck clean. No matter how clean the pool is, if you don’t scrub and maintain the deck, even the slightest wind can spread all the dirt back to your pool.

Skim the pool every day to remove the debris and leaves. This is pool cleaning 101, and not just for the sake of preventing cloudy water, but for maintaining a healthy pool environment.

Take a shower before you jump into the pool. We understand that not everyone wants to take a shower before starts swimming in the pool, but our bodies are full of chemicals, sweat, and dirt that has accumulated during the entire day. Not to mention all the cosmetics we use. Try to make showering be a routine before swimming.

Maintain the proper pH levels. Improper pH levels are one of the main reasons why cloudy water happens at first that, but other than that swimming into a pool with pH levels below or above the optimum can be toxic and irritating to our skin and eyes.

Run the filtration system long enough. Water in water out. When using the filtration system, you need to make sure you’ve done a full cycle.

Follow the manufacturer instructions. Every type of pool comes with proper instructions how to maintain your pool and how to use an appropriate amount of chemicals. Make sure you stick with the recommendations.

Use a clarifier once in a while. In general, clarifier is not necessary, only when you tried every other option. But once in a while feel free to use it and to avoid further regrets.

Alright so How do I Get Rid of a Cloudy Pool?

Shock Your Pool

There are many reasons why your chlorine levels can be depleted. Among most common ones are the weather condition such as hot weather (due to the UV lights from the sun) or hot water for a prolonged time, lots of rain, excess of people, or having a low-quality testing kit that produces false readings and makes you use the wrong chemistry balance, etc.

Once you get a quality testing kit, and you get the results, the solution is pretty straightforward – shocking your pool. What you want to do in this case is to boost your chlorine levels up to 10 ppm. Problem solved.

Do A Proper Inspection (Clogged Filter, Filter Leak Or Poor Filtering) And Run The Filtration System Long Enough

Start by inspecting the filter, see if there’s something stuck in there that’s blocking it from running within its optimal performance. Filter leaks mostly happen if you are using D.E. filters. Unfortunately, there’s no easy way around this. You’ll have to check if there are broken grids and replace them. In case you are using a sand filter make sure you’re backwashing and rinsing your filter at least once per week.

Cartridge filters if handled correctly can last for about year and two, if the filter condition is poor, replace it with a brand new one.

Lastly, the filtration system should run long enough on a daily basis to purify the water. If the cloudy water is persistent, you want to increase the circulation time and get rid of the algae manually by using a wall cleaning brush attached to a telescopic pole.

Get A Vacuum Cleaner To Remove The Excess Of Sodium Bicarbonate

This is usually a temporary problem that happens when you added a bit too much soda. There are two possible scenarios to solve the problem in this case. You can wait for a few hours or a day for the cloudy pool water to clear by itself, or get rid of the excess of the sodium by using a manual or automatic vacuum cleaner.

Get DPD Drop Test Kit And Make Sure Your Ph, Alkaline And High Calcium Hardness Are In Balance

The pH levels mean how much potential hydrogen the water has or what’s the level of acidity or toxicity, what’s the alkaline (which is mineral) level. When you have unbalanced water, this can cause that foggy or cloudy look. For drinking water, anything lower than 7 is considered to be acidic (because that’s a perfect environment for growth and survival of bacteria), and anything above 7 is considered to be base.

When talking about pool pH levels you want them to be between 7 and 7.6. Even when we don’t drink the water, it can cause discomfort to our skin and swollen and burning eyes.

Let’s say you have high pH level, how do you decrease it? Simply, use muriatic acid.

How much you need? The bad news is that you cannot do this with water straps, the good news is that you can do this with high-quality test kit or a DPD drop test kit. Quality kits will do the calculation for you and help you run all the tests for acid and base demand, cyanuric acid, combined chlorine, and all the basic stuff such as bromine levels, pH levels, alkalinity, and calcium hardness . If not, you’ll have to do some math based on the gallons in your pool.

What if your pH level is high? If that’s the case, you need sodium carbonate or soda ash which you can buy from Walmart or your local store. For small pools or above ground pools, you need just a tiny amount to hit the recommended pH level.

But before you jump into raising the pH levels, first you need to test the alkaline levels. If you make this right, controlling the pH levels is easy or sometimes even unnecessary. You want your pool water alkaline level to be anything between 80-120 ppm.

How do you raise the alkaline level? With baking soda or also known as sodium bicarbonate. As we mentioned above if you use more soda than required you can use the vacuum cleaner or wait for a few hours to clear itself. But be careful, the baking soda can also increase the pH levels, so if you have a high level of pH already you’ll be better off with muriatic acid.

Lastly, calcium hardness. Basically, high or low calcium hardness means that you have unbalanced water. This is also known as floating calcium. What is the range that you should aim for? Between 150-440 ppm.

If you have calcium hardness below 150, you need calcium chloride to increase it, and this is important because your water might become corrosive. In case you have calcium hardness above 440 ppm you can use muriatic acid and vacuum the bottom of your pool to get rid of the excessive calcium (as we mentioned above).

Cloudy pool water means that you have hard water or you have high calcium carbonate levels, usually above 440, this is rare but even lower levels can cause this. However this should be your last step, generally fixing the alkaline and the pH levels would take care of the calcium hardness as well.

Do MPS Shock Or Add More Chlorine To Remove The Combined Chloramines

When you add ammonia to the chlorine, you get a chemical compound called chloramines. This is urine, sweat, body oils, cosmetics, lotion, and nitrogen combined with chlorine.

The result? A distinctive unpleasant smell, and of course a cloudy pool. Make no mistake, the chlorine itself does not cause odor. This is due to the chloramines which are also called known as combined chlorine.

What’s the solution? Very simple, just add more chlorine, plenty of it, liquid or granular makes no difference. You are going to get rid of the cloudy water and at the same time kill all the gems.

An alternative would be to do an MPS shock or use chlorine-free oxidizer called potassium peroxymonosulfate. Our recommendation is to go with chlorine and raise the chlorine level to 10-15 ppm.

Get A Pool Clarifier

Unfortunately, while this is a no-brainer, it’s often neglected factor when maintaining your pool. There are plenty of external factors that can cause your pool to be cloudy such as bird droppings, dead insects and organisms, trees and decaying leaves, pollen, algae, heavy rains, nearby construction developments during the season and what not.

One of the easiest solution to prevent the foggy pool happening at first place is to get a pool cover and protect your swimming pool while not in use. For the rest of the factors that we can’t probably control, our recommendation is to use the steps mentioned above.

However, if you find yourself racing the clock and you are looking for the fastest solution, the best quickest way to clean up the pool water and kill all the germs and bacteria is to use a pool clarifier.


As you can see, there are dozens of reason why you might be facing a cloudy pool water. We covered the most common ones which majority of pool owners are facing. But, before you jump into conclusion and start dropping all sorts of chemicals, it’s imperative to find out why you are having this issue in first place.

Do the basic steps first, check the equipment, especially the filter system, get rid of all the debris, do some basic skim brush and sweep, wait for an hour or so check if that solved the issue. If not, run the water balance tests by using a test kit and work your way up, check the alkaline levels, the pH levels, the chlorine levels, and act accordingly to the findings. Next time this happens, you’ll know exactly what to do.

Last but not least, try to put into account all the external factors we mentioned above to prevent this from happening.