How Often Should You Shock Your Pool?

Written by Michael Dean
July 10, 2023

pouring pool shock into pool and a calendar

Keeping your pool clean and sanitized can take time and effort, especially in the summer when the pool is getting the most use. When swimmers use the pool, germs, bacteria, oils, and other unwanted deposits accumulate in the water, neutralizing the efficiency of your chlorine. Shocking your pool is the best way to eliminate contaminants and clean your pool water.

It is helpful to understand how to use pool shock and how often it’s required. As a pool owner, you’ll need to look for the warning signs for when to shock your pool. I will cover the basics below and address a few common questions on pool shock.

Main Takeaways

  • You should shock your pool once a week, depending on how much use it gets.
  • Shocking your pool helps reduce the buildup of chloramines and undesirable bacteria that have saturated the water.
  • Avoid shocking your pool too often since it might wear down pool equipment.
  • The best time to shock your pool is during dusk and evening hours.

How Often Should You Shock Your Pool?

Generally, I recommend shocking the pool about once a week, depending on how much you use your swimming pool.

Pool shock frequency can be more or less than once per week depending on several factors, such as weather, pollutants in the air, and how dirty your pool is. In addition, specific scenarios will require you to shock your pool, such as after parties, storms, periods of sunshine, when you open your pool for the season, or due to algae infestations and cloudy water.

However, the signs that your pool needs to be shocked won’t always be so obvious, so you’ll also want to ensure that you test the pH and chlorine levels every few days to ensure you shock the pool often enough. Another telltale sign that your pool needs to be shocked is if it is emitting a strong chlorine smell. This chlorine smell indicates that the chlorine molecules have fused with oils and other deposits in the water to form combined chlorine.

Why Should You Shock Your Pool?

Shocking a pool is necessary to reduce the buildup of chloramines and undesirable bacteria that have saturated the water. Since human sweat, oils, hair, and urine can accumulate in water over time and combine with chlorine, shocking the pool helps to destroy any elements of this unwanted combined chlorine. Combined chlorine also gives your pool that unpleasant smell of ammonia, which many people associate with public pools. Contrary to popular belief, the so-called “chlorine smell” means the pool is dirty, not clean!

To sum up, you should shock your pool because it will oxidize combined chlorine, replace it with free chlorine, cut down on the residual bacteria in your pool, and make your pool much safer for swimmers.

Can You Shock Your Pool Too Often?

It is possible to go overboard when it comes to shocking your pool. While it may seem harmless to continuously shock your pool to prevent algae growth and accumulation of bacteria, it isn’t a good practice to follow. Here are the reasons why it’s bad to shock your pool too often. You should also make sure to add the right amount of pool shock.

Bad For Pool Equipment

Shocking your pool too often is also not good for your pool equipment. You might end up corroding vital machinery, such as the pool pump or heater. While shocking your pool once a week shouldn’t damage your equipment, you should avoid doing it too often. A lot of pool equipment, including heaters and filters, are sensitive to pool chemicals. So, exposing them to these harsh chemicals unnecessarily at a stronger dose leads to expensive repairs or replacements.

Dangerous For Swimmers

If you shock your pool too often, your chlorine levels may jump up to dangerous levels. Ideally, your chlorine levels should lie between 1-3 ppm, but too much shock too often can spike the chlorine even to 10 ppm! Swimming in waters with too much free chlorine can cause your skin to itch and burn and may even discolor your hair and swimming suit.

Pool Liner Staining

Particularly if your pool liner is made of vinyl, you want to be careful not to use more pool shock than necessary. The pool shock can harm the liner, which can be an expensive fix. Even for those with concrete pools, too much shock can be harmful to the plaster, causing stains and corrosion.

Signs That You Should Shock Your Pool

You should shock your pool once a week, but you should also consider shocking your pool in the following situations:

  • If there is a strong chlorine smell wafting from your pool.
  • At the start and end of a pool season.
  • If there is stool or urine in your pool.
  • After a heavy rain, thunderstorm, dust storm, sunny weather, or unusual weather activity, if your pool was uncovered.
  • After a pool party or any event with a lot of people or pets in the pool.
  • If your water looks whitish, opaque, cloudy, or discolored.
  • If you have stubborn algae growth that won’t go away.
  • If your pool is dangerously below the free chlorine levels of 1-3 ppm.
  • If wild animals, such as bears, wild hogs, or raccoons, have entered your pool.

When To Shock Your Pool

The best time to shock your pool is always in the evening or at night. The sun’s UV rays break chlorine down quite rapidly, which hampers its ability to effectively oxidize bacteria and other unwanted elements in the pool. Shocking your pool at night lets the chlorine work much longer, giving it and the pool pump filter plenty of time to remove any pathogens from the water. If you absolutely must shock your pool during the day, try using non-chlorine pool shock, stabilized chlorine, or a chlorine stabilizer like cyanuric acid to protect the chlorine from the sun’s rays.

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Frequently Asked Questions

What Happens If You Shock A Pool Without The Pump Running?

If you can avoid it, do not shock your pool without the pump running. If you do so, you will risk the chlorine being patchily distributed due to lack of circulation. This would hurt the effectiveness of the shock treatment since the water will not be uniformly sanitized, leaving your water still at risk of an algae infestation or full of bacteria. Excess chlorine in some areas of the water might also stain your pool walls and equipment. However, with that said, there is a way to shock a pool without the pump running.

How Long After Shocking Can You Swim In The Pool?

You must wait at least 24 hours to hop into a pool once it’s been shocked. This is so that the treatment has time to work, clean the water, and stabilize it. Getting into water with an excess amount of chlorine can lead to symptoms such as redness and pain in your eyes, burning and rashes on your skin, and irritation in your nasal passages and lungs. I recommend waiting for the shock to dissipate naturally by the next day and testing your water to ensure it is safe to swim in again. The pH levels should be between 7.2 and 7.6, and the chlorine levels should be between 1 – 3 ppm.

Have more questions? Let me know; I’m always happy to help.

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