Pool Water Cloudy After Shocking? Here’s What To Do

Written by Michael Dean
September 28, 2023

cloudy pool water after shocking

Nothing feels better on a hot summer’s day than dipping into a fresh, sparkling swimming pool. But before you can fully enjoy your pool, you’ll need to ensure it is clean and safe. One regular part of your maintenance routine should be a weekly shock. While shocking your pool should typically clear up the water within 24 hours; in some cases, your pool water may be cloudy after shocking.

Read ahead to troubleshoot reasons your pool could be cloudy after shocking, pointers on how to fix it, and tips on preventing cloudy water from reappearing.


Main Takeaways

  • Your pool water will likely be cloudy immediately after shocking as the granular pool shock dissolves.
  • Reasons your pool water is cloudy after shocking could be an issue with your filtration system, poor pH levels, or high levels of calcium, CYA, or contaminants.
  • You can fix cloudy pool water by troubleshooting a faulty filter, adding a higher, second dose of shock, or using a clarifier.
  • To prevent cloudy pool water, consider investing in a pool cover and manually cleaning the pool yourself on certain occasions.

Reasons Why Your Pool Is Still Cloudy After Shocking 

There are several causes behind cloudy water after shocking the pool.

The most common cause? It’s too soon! Remember that immediately after shocking, your pool water may be cloudy as the shock granules may not have yet dissolved. Give the chlorine shock time to dissolve and circulate throughout the swimming pool.

However, if your pool is still cloudy after 24 hours, you have another issue on your hands. Here are the reasons why your pool water is cloudy after shocking the pool.

Unbalanced pH Levels

The first step to figuring out what’s wrong with your water is to test the water chemistry. It zeroes down on possible suspicions or eliminates obvious choices since pH imbalance is often the cause of something wrong with the water. Remember, pH needs to be between 7.2 – 7.6 for the shock and chlorine to kill bacteria or other unwanted germs in the water.

So, if your pH is unbalanced before or after shocking the pool, there could be agents in the water that neutralize the free chlorine elements of the pool shock, rendering the treatment ineffective and causing chloramine to form. Chloramine, also called combined chlorine, contributes to a cloudy appearance in the water.

Poor Filtration

Poor water filtration is one of the major causes of cloudy, murky water. If your water isn’t being appropriately filtered, your shock doesn’t get a chance to disperse throughout the entire pool. This may cause the shock to be concentrated in one area instead of your entire pool. And since the filtration system isn’t distributing the shock everywhere, you’re stuck with a pool that is still cloudy despite shocking.

You can trace cloudy pool water back to a compromised pool filter, a clogged impeller, or overused filter cartridges. Draw up a checklist of your filtration system and check for clogs, buildups, skimmer basket debris, or any cartridge cleaning. If everything seems fine, it could be that you’re not running your filter long enough after shocking the water. You should run your filter for at least 6 hours after administering a shock treatment.

High CYA Levels

Cyanuric acid, or CYA, stabilizes chlorine levels in your pool. It acts as bubble wrap for free chlorine, protecting it from the sun’s ultraviolet rays. But high cyanuric acid levels can cause water to turn cloudy after shock. High levels of cyanuric acid can also lead to the formation of calcium carbonate, which can cause cloudiness and scale on pool surfaces.

If you suspect this is the case, you could try replacing a portion of your pool water with fresh water to lower cyanuric acid levels in the pool water. CYA levels in the pool need to be less than 50 ppm, so don’t go overboard with adding it to your water. Additionally, stabilized chlorine, like dichlor and trichlor, has CYA included. So, instead, try using unstabilized chlorine to shock your pool, such as cal-hypo.

Calcium Hardness

Too much calcium in water can cause the formation of calcium carbonate, which makes the water appear chalky or whitish. Further, when calcium carbonate forms, it can cling to surfaces in the pool, such as the walls and floor, possibly damaging the infrastructure. High levels of calcium can also raise the pH levels of the pool. Imbalance usually results in the formation of cloudy water after shocking. If you suspect this is the reason, test your pool water for calcium hardness – it will need to be in the 200 – 400 ppm range to be ruled out as a possible culprit.

An excess of calcium may also be caused by using cal-hypo as pool shock. So, if your pool water is cloudy after shocking, try using another pool shock chlorine. Or use a non-chlorine shock.

High Levels of Contaminants

Another reason for cloudy water after shocking is that the level of contaminants present in the water is too high for a single dose of shock to fix. This especially stands true after a significant event, such as a large social gathering or a major storm. Rainwater can easily mess with the pool’s pH levels and introduce many foreign contaminants – more than one dose of shock can handle.

In addition, some new pool owners also make the easy mistake of pouring shock into the pool during the day, when there is strong sunshine, which would rapidly kill off any fighting chance the chlorine has against the heavy contamination.

How To Fix Cloudy Pool Water After Shocking

Once you’re sure of what might be the issue with your pool, follow the steps ahead to fix cloudy water after it’s been shocked.

Clean and Run the Pool Filter

Run the filter system for 24 hours. But before you do, make sure everything is in working order. Service your pool filter and ensure it’s clean and in good working condition. Replace any dirty or overused cartridge filters and empty the skimmer basket if it’s full of debris. If you think something else might be the problem with the system or if the filter is stalled, call a professional to look at it immediately.

Use a Clarifier

If there are too many microparticles in the pool, try adding a clarifier to the water to help clear up the cloudiness. A clarifier is a chemical added to the pool water to help clear up the water by clumping together small particles so they can be more easily filtered out.

Clorox Pool&Spa Super Water Clarifier

Clorox makes a good clarifier that I recommend for most pool owners trying to solve a cloudy pool problem.

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I may earn a commission if you make a purchase, at zero additional cost to you. This in no way impacts my research process or opinions.

Test and Adjust the Water

You must test and adjust water chemistry according to recommended guidelines for your pool before shocking. Improper alkalinity, calcium, or pH levels can cause a lot of trouble and cloudy water. So, to avoid cloudy water, ensure your water chemistry is properly balanced before shocking. You should also make it a habit of testing the water weekly.

Partial Refill

If the pool water is still cloudy after trying the above steps, consider doing a partial drain and refill to dilute any remaining contaminants and re-attempt the shock. Keep monitoring the water chemistry and adjust it if needed. If the problem persists, consider getting in touch with an expert to pinpoint the problem. And don’t swim in your pool while it’s cloudy!

How Long Does It Take For Granular Pool Shock To Dissolve?

In most cases, your pool water will be cloudy immediately after shocking. But cloudy or milky water after shocking is a regular occurrence if you use granular pool shock, and it should clear up within an hour – as long as your pump and filter are running normally.

The time it takes for granular pool shock to dissolve will depend on several factors, such as the size of the granules, the water temperature, and the amount of shock added to the pool.

Typically, granular pool shock will dissolve within a few minutes to an hour, although it can take longer for larger granules to dissolve if the water is colder. Distributing the shock evenly throughout the pool helps with consistent dissolution. This can be done by pre-diluting the shock in a 5-gallon bucket and manually walking around the edge of the pool’s perimeter, pouring the shock at a steady pace.

How To Prevent Pool Water From Becoming Cloudy

Here are some simple pointers to follow when it comes to preventing your pool water from turning cloudy in the first place entirely:

Regular pool maintenance: Keep your pool as clean as possible. Pool maintenance can be a full-time job for some owners, and it’s tempting to lag on the chores and pool upkeep necessary to keep your pool safe and hygienic. This also involves having your pool equipment serviced regularly. After all, it does much of the legwork to keep that water clear and clean for you and your family.

Use a pool cover: Lower the chances of debris and contaminants entering your pool by covering the water when not in use. Solar covers are usually excellent for keeping the water warm and clean. If you have a higher budget, you could consider an automatic pool cover for maximum ease of use.

Maintain proper chemical balance: This cannot be stressed enough. You should be testing your pool water regularly. You should test once a week (twice during high usage), before and after adding pool chemicals, and after any major weather events. Keeping your pH, calcium hardness, and alkalinity at the ideal levels can make the world’s difference in keeping your water nice and clear.

Cloudy pool water (even a cloudy salt water pool) isn’t too challenging to resolve on your own, but if you’re struggling with a particularly difficult problem, reach out to me, and I’ll be happy to help!

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