How Long Should You Wait to Swim After Shocking Your Pool?

Written by Michael Dean
July 11, 2023

shocking a swimming pool and waiting time

During the summer months, it’s normal for the pool to get a bit crowded with visitors and friends who need a break from the heat. And, of course, more use means the pool will get dirty more frequently, even if you’re doing your absolute best to keep up with your maintenance routine. Especially during high usage months, you should shock your swimming pool regularly. This ensures your pool is clean – even after a pool party! But after shocking the pool, how long do you have to wait before you can jump back in to enjoy the cooling water again?

In this article, I will answer this question and cover other safety elements concerning pool shock and other pool chemicals.

Main Takeaways

  • It is usually safe to swim in a pool within 12-24 hours after it’s been shocked, but you should test the water before doing so to ensure the levels are safe.
  • It can take around 15-30 seconds for granular pool shock to dissolve, although this may depend on various factors.
  • Swimming too soon after shocking your pool can cause severe olfactory and respiratory issues and might result in an emergency room visit.

How Long Should You Wait to Swim After Shocking Your Pool?

It is generally safe to swim in a pool 12 hours after shocking it. However, the time you should wait is subject to the size of the pool, so in some cases, you may be waiting up to 24 hours or more! With that said, typically, by the next day, a few hours of strong sunshine should make the water safe to swim in again unless you’ve also added cyanuric acid to the pool.

Regardless of whether you wait 12 or 24 hours or anything in between, before getting in the pool, make sure you retest the water to ensure it’s safe first (after the filter has had a chance to circulate water for a few hours after shocking). Check the pH levels and the chlorine contents of the water. A basic strip or liquid reagent test kit should be enough to check these chemical levels.

Your chlorine levels should be between 1 and 3 ppm (parts per million), and ideal pH levels range from 7.2 to 7.6. If the water’s chemical levels are off, let your pool filter continue to circulate water instead of jumping into your pool. Re-test your pool water and adjust your pool chemicals if they are still outside the recommended ranges after a few more hours.

How Long Does It Take For Shock To Dissolve?

The amount of time it takes for pool shock to dissolve varies. It can depend on the following:

  • The type of shock being used (liquid or granular)
  • The strength of the chlorine
  • The size of the crystals if the shock is granular
  • The manufacturer

Liquid pool shock doesn’t require any dissolving since it already comes in a liquidized form. On the other hand, granular pool shock, such as cal-hypo, may take around 15 seconds to dissolve in warm water. It can take longer to dissolve in colder water during winter months, especially if there is no circulation.

When it comes to granular shock, to prevent uneven dissolution, you should pre-dissolve the required amount of shock in a 5-gallon bucket of warm water. Then, stir your solution with a mixing rod for around half a minute, and walk around the perimeter of your swimming pool, slowly pouring the solution into the water.

What Happens If You Swim Too Soon After Shocking Your Pool?

It may be challenging to hold back from taking a dip, especially on those hot summer days, but if you swim too soon after shocking your pool, you can risk damaging your skin, eyes, and even lungs.


Excess chlorine can damage the surface layer of the skin, leading to itchiness, burning, and dehydration. If your skin is more sensitive, it may even lead to rashes, especially in sensitive areas, such as lips, armpits, and the groin.


Excess chlorine can also cause irritation and redness in the eyes. The skin around the eyes can also get extremely dry and itchy. In serious cases, you may encounter severe burning and partial vision loss. Other olfactory organs, such as your ears and nostrils, might also suffer the same symptoms if exposed to such water.


Chlorinated water releases fumes into the air due to the acid produced, and long-term exposure can lead to lung damage. Inhaling super-chlorinated water can be a cause for immediate medical attention.


While chlorine in and of itself is not poisonous, its acidic by-products can be fatal with just a few gulps. Swallowing highly chlorinated water can also lead to digestive concerns, such as a burning sensation in your stomach or nausea and dizziness.

If you or anyone you know accidentally gets into a recently shocked pool, the best protocol would be to have a cold rinse in the shower or call a doctor if needed. However, your safest option is to avoid getting into the pool in the first place. You should also place a warning sign nearby to let others know the pool has been recently shocked.

How Long Should You Wait To Swim After Adding Other Pool Chemicals?

When adding other water-balancing chemicals, it is advisable to wait at least a few hours before getting into the water. It is best to err on the side of caution and wait for the recently balanced water to cycle through the pool pump filter at least once, which is around 2 to 4 hours. I have more specific guidance in the articles below:

I strongly recommend testing your pool before every swim session, regardless of whether you have recently added chemicals. This will help keep you and your family safe from unhygienic water or water that has too high a level of chemicals. After all, pool chemicals are volatile substances, and pool chemistry levels are constantly in flux. Safety and caution should be every pool owner’s top priorities.

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Frequently Asked Questions

When should you shock your pool?

You should shock your pool following parties, major storms, if there are symptoms of algae infestations, if the water looks cloudy, or if there are traces of feces in the water. In addition, you should ideally shock your pool at the start and finish of your pool season and every week during the pool season. You should also shock your pool if there is a powerful smell of chlorine coming from the pool – this is a sign of dirty pool water.

Can you shock a pool without the pump running?

It is not recommended to shock a pool without the pump running. The pump filters and circulates the chemicals you add to a pool and is vital to the process of shocking a pool. If you cannot use a pump, you must manually filter and circulate the water using a pool net and a robotic pool cleaner.

Can you shock a pool without chlorine?

Yes, there are products available if you wish to avoid using chlorine to shock your pool, such as potassium peroxymonosulfate. While they are not as effective as chlorine in killing germs and algae spores, they are often less costly to use and allow you to use the pool within 15-20 minutes after it is added to the pool.

Also, I feel like it’s important to note that you shouldn’t swim in your pool while it’s cloudy, either.

Do you have more questions about shocking? Let me know!

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