Swiming Pool, Swimming FAQs

How Long Can You Swim After Shocking The Pool?

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How long can you swim after shocking the pool? Everything you need to know about pool shocking, including its various types and how long you should wait to swim after shocking a pool, is provided below. Safe swimming is ensured by knowing how long to wait after shocking a pool.

What Is Shock?

You can increase the amount of free chlorine in your pool by shocking it. Increasing free chlorine also makes sure that bacteria and algae are killed. It’s important to remember that shocking the pool involves adding chemicals to the water to create the ideal chemistry for chlorine to function properly. Your shock also contains various chemicals, including potassium peroxymonosulfate, dichlor, lithium hypochlorite, and calcium hypochlorite.

Swimming pool shock is a powdered form of chlorine used to treat pool water in order to make it safe and healthy for swimming. Shock is an essential part of pool maintenance regardless of the type of chlorine used for daily sanitation, including salt water systems.

If we want to go a little deeper, there are three types of pool shock available for purchase to treat your water. The first is calcium hypochlorite (also known as cal-hypo), the second is sodium di-chlor (also known as di-chlor), and the third is liquid chlorine. They each have advantages, but they are all effective at treating pool water.

What distinguishes shock chlorine from regular chlorine? Granular chlorine, liquid chlorine, chlorine tablets, and granular shock all have active chemicals that sanitize your pool; the only difference is the strength of the chemical and how you’re supposed to use it.

Why Do I Need To Shock My Pool?

While some perform this task as routine maintenance, others do so to remove algae, clear a cloudy pool, or boost the amount of free chlorine. Typically, you shock your pool when

  • There are high levels of organics in the pool (leaves and debris)
  • The pool has algae
  • The pool is cloudy
  • Chlorine levels are extremely low

When Should Your Pool Be Shocked?

After contamination, such as after a pool party or a lot of rain, shocking helps by bringing the water’s pH level back to normal. Additionally, if there is already a significant algae bloom, it is a more effective remedy than algaecide.

Pool shock also aids in the elimination of chloramines, or combined chlorine, and revitalizes your existing chlorine. This allows your regular chlorine to keep sanitizing your water as usual.

How Long Does It Take For Shock To Dissipate?

Alkalinity, pH, and calcium hardness are among the other pool chemicals that adjust levels, and they all dissolve in your pool’s water in less than an hour. However, since chlorine-based pool shock contains a strong, concentrated dose of chlorine, it takes longer to act in the water.

To quickly raise your chlorine levels, add chlorine shock, such as dichlor or cal-hypo shock. By quickly increasing your chlorine levels above 10 ppm, this eliminates contaminants like chloramines, algae, and other pollutants. Even though the high chlorine content is great for eradicating chloramines and killing algae, swimming in it is not safe. Because of this, you must wait at least 8 hours after adding shock to your water or whenever your chlorine levels return to a safe level (ideally 3 ppm or less than 5 ppm). Always recheck your pool’s water chemistry after shocking it using a test kit or test strips.

How Long Can You Swim After You Shock The Pool?

If you do an internet search, you’ll find rough estimates that range from “immediately” to “24 hours.” But the REAL response is: Don’t leave the article just yet; the real answer will be revealed in a moment.

You’ve probably heard that it’s best to shock your pool in the evening or at night, after the sun has set. That’s because shock acts like a vampire, soaking up the free chlorine you’re trying to add to your pool by adding shock, which is what sunlight’s UV rays do. It’s therefore simpler to simply say, “Shock at night and keep the filter running overnight; test the pool water in the morning before you swim.”” But does it really work out that way all the time? Assume you’ve experienced (surprise!) “body waste” situation. For example, say you had planned a pool party for the afternoon but it’s 10 a.m. and baby Chloe’s swim diaper didn’t quite hold up as intended in the pool. Ah, yes. Isn’t life full of adventures?

Can you swim in the pool after it has been shocked? You must shock the pool in broad daylight. How long must pass before you are able to swim? Before allowing anyone to enter the pool, you should wait one hour for every pound of shock product added and test the water to make sure the pH and chlorine levels are within the recommended range.

As a refresher, for safe swimming you need a pH of between 7.2 and 7.8ppm and a free available chlorine level of between 1-4ppm.

Factors That Determine How Long To Wait To Swim After Shocking


Type Of Shock

Cal-Hypo & Sodium Hypochlorite

Most of the time, when we refer to shocking a pool, we mean using calcium hypochlorite (cal-hypo) or sodium hypochlorite. These two substances are both chlorine-based. The former is liquid chlorine, while the latter is granular chlorine that is frequently marketed as “pool shock.”

You must wait until the high chlorine levels reach 5 ppm before swimming since both of these are chlorines. especially if any of the pool enthusiasts have sensitive skin. Chlorine’s reaction with skin’s proteins and fats can result in painful burns.

Furthermore, even if you don’t feel anything right away, swimming prior to this occurs is still dangerous. You might have a delayed response later.

Potassium Monopersulfate Pool Shock

Additionally, chlorine-free pool shocks are offered. The one of those is potassium monopersulfate.

You can wait as little as 15 minutes before diving into the pool if you use this product, which is a benefit. Since potassium monopersulfate is entirely oxygen-based, it oxidizes to disinfect swimming pools. This improves the pool’s chlorine’s efficiency.

However, there are serious drawbacks to this kind of shock, which we’ll go over in another article.

The Amount Of Shock Used

More time must pass before swimming after a stronger dose. Even so, there are times when bright sunlight can help reduce the amount of time you must spend away from your pool.

Algae Content

More extensive shocking, which can last for several days, is necessary for pools with higher algal bloom concentrations. The longer it takes to effectively disinfect your pool before use, the more algae it has.

Pool Maintenance

Less chlorine is required for a pool that is well-maintained. This shortens the time that must pass after shocking before entering the pool. The inverse is accurate. To reach the necessary standards of pool hygiene, a pool that is not regularly maintained will need higher doses of chemicals.

Manufacturer’s Instruction

I always make use of the information on the back of the container containing the shocking substance. You can better use the shocker if you are aware of the precise parts that are in it.

There are various usage instructions included with each shocker.

Pool Type: Indoor Or Outdoor

More quickly than indoor pools, outdoor pools will be ready for swimming. Natural chlorine level reduction occurs when sunlight’s UV rays “burn” off the chlorine. The sooner your pool is safe to swim in after being shocked, the more sunlight it receives.

When Is It Okay To Return To A Shocked Pool?

According to Alan, depending on the size of the pool, you should generally wait up to 24 hours before diving in.

Before you or anyone else enters the pool, Alan advises testing the pH and chlorine levels to make sure they are within the proper range if you are in charge of pool maintenance. (The Centers for Disease Control and Prevention recommend that the pH be between 7.2 and 7.8 and that the chlorine concentration be between 1.0 and 4.0 parts per million.)

Why Can’t You Swim Now That The Pool’s Been Shocked?

Because the chlorine hasn’t dissolved in the water after the pool has been shocked, you cannot swim. The shock therapy doesn’t wear off for several hours.

The water will lose a lot of chlorine, and you’ll need to add more over the course of the following week. To help the chlorine dissolve more quickly, make sure the pool is circulated.

Following a water shock, swimming can result in the following:

  • Your hair could change colors (typically green or bright white). Ever notice how bleach colors everything it comes in contact with? Due to the chlorine content, this process takes place. Your hair and clothing will get dyed much faster with pool shock because it contains a lot more chlorine than bleach.
  • You’ll undoubtedly have skin dryness, especially around your elbows, knees, and other areas where the chlorine sticks. The best way to remove chlorine is with soap and water because it dries everything it comes into contact with. To relieve the itching, you might also want to use aloe vera.
  • There’s a high chance that your eyes will burn if you open them underwater. Pain and redness will be present in significant amounts after swimming through pockets of pool shock. If you go swimming within 24 hours of adding shock, make sure you have goggles on. If you ever open your eyes underwater, it is actually advised to wear goggles.
  • You’ll probably have itchy skin from head to toe. Itching is brought on by the dryness and redness. The less chance you have of experiencing persistent itching, the sooner you scrub and rinse the chlorine off your skin. In the vicinity of exposed areas, itching is much more prevalent.
  • There’s a small chance that nothing bad could happen. Chlorine pockets are dropped in during shock treatments. Any of the aforementioned problems won’t arise if you manage to avoid swimming through the chlorine pocket. Because it’s extremely uncommon to avoid chlorine, be sure to take the steps listed above to remove it from your body.

What Happens If You Enter A Pool That Was Recently Shocked?

You’ll experience a number of health issues if you swim in a pool that has recently been shocked. These problems include things like dry skin, peeling, breathing difficulties, and more. Your eyes can be burned and your hair color can be altered by the high chlorine content. Pool shock is a highly concentrated chlorine that needs to be handled carefully.

Observe these steps if you unintentionally enter a pool that has recently been shocked:

  1. Get out of the pool immediately. It’s critical to reduce the amount of chlorine and other corrosive chemicals that contact your skin while swimming. Chlorine makes up the majority of pool shock, but there are a few other concentrated filler ingredients that can be uncomfortable. Grab a towel and exit the water quickly.
  2. Wash the chlorine off of your body with a garden hose. To get rid of the majority of the pool shock, spray the entire body with the hose. Concentrated pool shock is extremely harmful and can result in a number of health issues. To get rid of any chlorine granules or liquid, scrub your skin and hair.
  3. Take a warm shower with plenty of shampoo and soap. Scrub the chlorine from your skin and hair using a sponge or brush. The garden hose tip helps you avoid bringing chlorine inside and staining everything, but it won’t do much for skin rashes and hair fading.
  4. Use body lotion and hair conditioner to bring the moisture back to your skin and hair. It’s important to use a few hydrating products to prevent cracking and discomfort because concentrated chlorine dries out your skin and hair. By using this technique, peeling and redness are also prevented.
  5. Test the pool’s chlorine levels and ensure they’re balanced. You should not only wait until the chlorine level is below 6 ppm before swimming, but you should also determine if you removed too much shock. When you exited the pool, you unavoidably carried some of the granules and liquid with you because they stuck to your body.

If you know how much shock to add to the pool, these risks are significantly reduced. By using too much shock, you run the risk of causing things like eye irritation and hair dryness. If there isn’t an algae bloom, your chlorine shouldn’t rise too high. Never enter a pool that is overgrown with algae or shock.

How Can I Determine Whether Swimming In My Pool Is Safe?

The first thing you should do is adhere to the instructions on the chemicals you used to shock your pool. For your safety, make sure to carefully read and abide by the instructions.

When you’ve complied with the rules and want to confirm that the pool is safe for swimming, check the chlorine levels. Swimming is safe once chlorine concentrations are below 5 ppm (source). With a testing kit, which you can purchase from any pool store and is affordable and simple to use, you can check the chlorine levels in your pool quickly and easily.

What Should I Do If I Add Too Much Chlorine To A Pool?

If you are a novice, it might take some time to balance the pH levels properly; even seasoned professionals occasionally make mistakes. What options do you have if you accidentally add too much chlorine to your pool?

Bringing in some sunshine is the most organic solution to the problem! 2-3 hours of sunshine will reduce the chlorine levels by up to 90%. If you can’t do this, you can try using neutralizing agents like sodium thiosulfate and sodium sulfite or a chlorine neutralizer from your neighborhood pool store.

Consider replacing the water as a possible option. Although it can be time-consuming, this is a possibility. Additionally, keep in mind that you will need to check all of your levels, not just the chlorine, once the new water is installed. Alkalinity and calcium hardness are included in this. If all else fails, get a professional to take a look rather than taking a chance by swimming in a dangerous pool.


It’s likely that something isn’t working properly if you need to add shock to your pool. Furthermore, there is a good chance that the balance of your chemicals has changed. The cost of attempting to fix your pool’s problems could be high. It is best to let the experts handle this in this situation.

You can trust the experts to take care of it now that you are aware of how long it takes to recover enough to swim in a shocked pool.