Owning a pool isn’t all fun and games; it takes time and effort to achieve crystal clear water. One of the fastest, most effective, and most popular ways to address a dirty pool is to shock it. However, many homeowners fail to realize that the cause of cloudy water can sometimes be the shocking process itself.
If you shock your pool and find it murky afterward, don’t panic! It happens sometimes. Once you find the cause, you can determine how to fix it. This article will dig into the logistics of shocking your pool and how to clear out the lingering cloudiness.
What Does Shocking a Pool Mean?
Shocking your pool involves pouring chemicals into the water to raise its chlorine level. The goal is to increase the chlorine level enough to kill contaminants like algae, bacteria, and chloramines, which will usually clear out any cloudiness in the water.
However, don’t let the strong smell of chlorine trick you into thinking your pool is clean. In fact, chloramines — the compounds that are formed when chlorine combines with oils, sweat, and urine — are the cause of this scent. You want your pool to be as odor-free as possible.
To shock your pool properly, it is essential that you understand the different types of chlorine, listed below:
- Free chlorine (FC): “Free chlorine” refers to the amount of all active chlorine types present in the water. Ideally, it should remain between 1 – 3 ppm.
- Combined chlorine (CC): “Combined chlorine”, on the other hand, measures the used chlorine. While used chlorine is still in the pool, it has a weaker sanitizing power than FC. Keep this level below 0.2 ppm.
- Total chlorine (TC): This number refers to the sum of the FC and CC in your pool.
When your free chlorine level hits zero or your combined chlorine level reaches 0.5 parts per million (ppm), it’s time to shock your pool. The goal of shocking your pool is to reach breakpoint chlorination, which is when you have enough free chlorine in your pool to kill chloramides.
Why Does a Pool Get Cloudy After Shock?
You shock your pool to clean it, but one of its potential side effects is leaving the water cloudy. When the water’s chemical and mineral levels are out of balance, adding chlorine can cause a reaction, which can cause this cloudiness. However, there are other reasons why your pool can get cloudy after a shock session. Here are some of them:
Contrary to popular belief, shocking the pool is not enough to keep it in tip-top shape. You also need a high-quality filter that works properly to achieve your desired results. If your filter is not up to par, it doesn’t matter how many times you dump chlorine into your pool; you will never achieve crystal clear waters. After all, chlorine can kill any contaminants in your water, but it cannot remove them from your pool for you.
High Calcium Hardness Levels
Another factor to consider is the water hardness in your area, as hard water will become murky much faster. For instance, if you live in an area that releases tap water with over 500 ppm hardness, pouring calcium hypochlorite to it adds 5 ppm for each pound of the chemical. Ideally, you should aim for 120 to 220 ppm hardness levels to keep your water crystal clear.
High pH Levels
Since shocking a pool involves massive doses of chlorine, you can expect various reactions from the process. For instance, if you have high levels of the wrong chemicals, mixing them with chlorine can cause your pool water to turn milky after shocking it.
If your pH level goes beyond 7.6, you’ll waste your chlorine. It’s best to look for a low pH level between 7.2 – 7.4 during the shocking process.
High Levels of Cyanuric Acid
Cyanuric acid — also referred to as CYA or stabilizer — is a common chemical used by many homeowners to prevent chlorine loss. However, too much CYA can cause the water to turn cloudy when you shock it. Check your CYA level monthly to ensure that it stays below 50 ppm.
Lack of Pool Clarifier
A pool clarifier gathers particles that turn your pool water cloudy and binds them together to create larger granules that your filter can catch. Using a clarifier after shocking your pool is crucial to keeping the water clean.
How to Clear a Cloudy Pool After Shocking It
Usually, any cloudy pool water that happens as a result of shocking is temporary. You typically don’t need to do anything but wait, as it should clear up overnight. However, if you still have a murky pool after 24 hours, here are some potential causes of your pool’s prolonged cloudiness and how you can solve these problems:
Problem: Filtration System
If you want to say goodbye to cloudy water, check your filtration system. Make sure it is clean and free of buildup, your skimmer basket or pump bucket is cleared of debris, and your filter media is not worn out.
Additionally, run your filter for longer than you typically would. When handling a cloudy pool, run the water through the filter system anywhere between 8 to 12 hours per day.
Problem: Unbalanced Water Chemistry
When your water’s calcium hardness, pH, and alkalinity get too high, they can affect your pool’s plumbing. This can cause quite an array of issues in your pool, from poor filtration to bacterial growth. The ideal levels for the above are as follows:
- Calcium hardness: 120 – 220 ppm
- pH: 7.4 – 7.6 ppm
- Alkalinity: 100 – 150 ppm, ideally 125 ppm
Next time, before you shock your pool, check its chemical levels first. Once you balance them out to the levels above, your filtration system will get your pool back to its usual clarity.
Problem: Low Chlorine Levels
If you shocked your pool and didn’t achieve the desired results, you might not have used the right amounts of chlorine. Without enough of this chemical, pathogens and bacteria can still form in its presence, causing the water to get cloudy. The appropriate amounts of chlorine also sanitize the water from bodily contaminants like sunscreen and sweat.
Before you shock your pool again, test your FC, CC, and TC levels. Next, remove excessive debris, like leaves, as they can cause chlorine levels to drop drastically. Afterwards, add enough chlorine to achieve breakpoint chlorination, and then give your pool time to adjust. The cloudiness should clear away within a day.
Frequently Asked Questions
Why Do Pools Get Cloudy After Shocking?
Having cloudy or milky water after shocking is not always a bad thing. Sometimes, adding water after the process will get your pool cleared up in about an hour. As long as your pump and filter are running accordingly, you shouldn’t have a problem clearing up the water.
If you add an algaecide, this may be making the pool milky, because it contains copper. This milky look can last for about one day without being a cause for concern.
However, if the cloudiness persists after 24 hours, check your filter and the levels of your chemicals, especially the chlorine levels. You might need to fix your filtration system, add some chemicals, or redo the shocking process to clear the cloudiness from your pool.
Can Too Much Shock Make a Pool Cloudy?
Yes, too much shock can make the water cloudy, but only temporarily. As your solution kills contaminants, you might see a dishwater-like shade on your usually crystal-clear pool. However, it shouldn’t be a cause for concern; this happens to the savviest of pool owners all of the time!
If you’re concerned about your shocking methods, know that it is essential to use the right shock type and amounts to achieve the desired results. If you have high chlorine levels and cloudy water simultaneously, the problem is not with too much shock; you have to do some investigating to find the underlying issue to address it. It could be your filtration system, chemical balance, or even mold growth.
How Long Do Pools Remain Cloudy After Shocking?
If you recently shocked your pool and now see a cloudy appearance, it could be a normal part of the process. In most cases, a murky pool after shocking is only a temporary setback that clears itself up within 24 hours.
If it’s taking too long, you can try filtering your pool and adding some clarifier to speed up the process.
Are Chlorines and Shock the Same?
No, they are not the same. Some shock brands contain chlorine, such as Calcium Hypochlorite, but others do not.
However, chlorine is a necessary sanitizer for maintaining a healthy pool. You can use it in high doses to shock your pool and raise the chlorine levels to achieve clear water.
How Soon Can You Swim After Shocking Your Pool?
Generally, it’s safe to use your pool again 24 hours after you shock it. However, it’s best to check the water’s chlorine levels before jumping in. Make sure it’s at 5 ppm before you swim, as too much chlorine can be uncomfortable or even dangerous for swimmers.
Shocking your pool is the best way to kill any contaminants like chloramines from your water. When left unchecked, these compounds can cause or aggravate respiratory problems like sinus congestion, choking, wheezing, asthma, and more.
It’s best to shock your pool once per week to maintain your pool’s health. Remember that it’s normal for the water to look cloudy after shocking, but for only about 24 hours. If you filter your pool water and add a clarifier but you still don’t achieve your desired results, you might be overlooking an underlying cause.
For instance, your filter could be faulty, or your pool’s calcium hardness, pH, and CYA levels might be out of balance. In such cases, the best thing to do is check. Test your filter and test the water for chemicals to determine the cause of the cloudiness.
If you’ve followed all of the tips from this article and you still can’t get your pool to its usual color, call a pool expert immediately.
About the Author
Stefan Schulz is the founder and owner of PV Pool Cleaner. He spent his college years working at Niagara Pools and Spas, one of the largest Swimming Pool and Hot Tub Dealers in the Eastern United States.
Today, he utilizes his background, experience as a pool owner, and the resources of his digital marketing agency, Orpical Group, to generate informative and engaging content for pool owners everywhere.