How and When to Shock Your Pool

The task of shocking a pool is considered an ordinary maintenance task to keep your pool clean. Readers new to the word ‘pull shocking’ may be misconstrued thinking it as an electricity-dealing task.

We assure you that it is a fundamental chemical-based project. As the task is related to the element called chlorine, it is also known as super chlorinating.  In the periodic table of chemistry, it is denoted as halogen. That means it produces salt after the reaction. So, don’t worry about hearing about the chemical business. We are here to make you understand a detailed figure about shocking a pool. After going through this article, you can determine when & how to shock your pool. So, stay in touch. 

What is pool shock? 

If we say in straight form, pool shock is a process of adding a chemical called chlorine to the water of a pool. A chemical-based process that increases the chlorine level of water & then fights against the contaminants.

Pool shock destroys organic wastes like bacteria, algae, etc. with fruitful results. Combined chlorine is the dealing issue here. It is usually created by fertilization elements, bird droppings, swimmer’s activity, and so on. 

Why do you need to shock a pool?

Don’t you want to swim in a crystal clear pool? The answer will be affirmative undoubtedly. Therefore, removing contaminants from the pool, it’s the necessary step to shocking a pool. You need to shock a pool to break apart combined chlorines. Combined chlorine is also known as chloramines.

It is harmful to pool water & so, it should be broken. If you shock a pool, additional chlorine will deal with combined chlorine. As a result, the situation of swimming in crystal clear water will be recreated. 

When to shock your pool?

Pool shocking isn’t a scheduled daily task. If you want to avoid this, you have to take proper care of your pool. Weekly maintenance sounds good but shocking will provide you with something better. There would be some incidents to deal with shocking your pool. These are:

Moss/algae are visible

When moss or algae are visible in your pool, it’s mandatory to take care of your pool. This incident creates a negative condition to swim. There are good possibilities of getting slipped & injured. In that case, experts recommend performing a super-chlorination process.

It requires a kind of powerful shock made with Cal-Hypo (Hypochlorite). If we talk specifically, you can use power powder pro. This quick-dissolving pool shock is capable of vanishing algae.

Pool over usage

Excess use of the pool pollutes the clean water of a pool. When a large number of people use a single pool for both a short or long time, the pool gets full of pollutants. It may seem your pool water is almost as clean as before. However, your pool water is polluted. To destroy the pollutants & make your pool tidy again, we recommend going through the pool shocking process.

Grand opening & closing

At the time of opening a pool, it’s recommended to shock the pool after balancing other chemicals. Shocking your pool will oxidize the substances & fight against pollutants. To increase the clarity of the water, this process is significant.

Usually, the pool is used for the whole summer & other seasons except winter. So, before closing your pool for the whole winter season, shock your pool. It will be effective against contaminants for a long time. After getting back before another summer, your pool won’t be full of moss.

Bad weather & natural disaster

Natural disasters depend on the region. If your pool gets in touch with a tsunami, tidal bore, or any kind of calamity, it’s a must to refry your pool. Even, it is a normal storm or heavy rain; you should shock your pool. These bring many kinds of dust with water & air. In that case, your pool becomes unsuitable to use. 

Chlorine smelling

Sometimes, the smell of chlorine can be felt from your pool. It happens due to the over-creation of combined chlorine at your pool. In that case, you need to break that combined chlorine by shocking your pool. Moreover, if swimmers complain that their eyes become irritated, be alert. You need to shock your pool immediately.

What is the difference between chlorine & shock?

There are different types of shock but the granular shock is highly used as a chlorinating shock. Calcium Hypochlorite is known as the most common form of granular shock. This type of shock contains 65 to 75 percent of chlorine. Shock is high-dose chlorine, which works for developing the chlorine level of your pool. On the other hand, chlorine is a sanitizer. Both chlorine & shock contain the same active chemical element. The difference is in the strength & the usage method. 

  • Liquid chlorine is not costly at all as it’s unstabilized. Chlorinating shock is stabilized & comes in tablet form, as it’s expensive.
  • Chlorine can be refilled as it comes with a container. Chlorinating shock is suitable for one-time use only.
  • Chlorine is non-scaling & leaves no remainder. The chlorinating shock leaves the remainder after reaction with combined chlorine.
  • Chlorine comes with a barrel as it’s difficult to move. Chlorinating shock is easily portable.
  • Chlorine is not suitable for preserving for a long time. Chlorinating shock can be stored for long periods. 

What are pool shock ingredients?

Let’s get introduced to the variations of chlorine & pool shock at a moment.

Two types of chlorine create impacts on the chemistry of your pool water. The last type is the combination of another two types.

Free chlorine:

It is considered a fast killer of contaminants. Besides, it is known as Free Available Chlorine (FAC). 

Combined chlorine:

As a part of our discussion, we already have told this. We are refreshing you by remembering chloramines. The presence of dead contaminants with chlorine, known as combined chlorine generates a bad smell of pool water.

Total chlorine:

The total amount of free chlorine & combined chlorine is called total chlorine. Let’s denote Total Available Chlorine as TAC, Free Available Chlorine as (FAC) & Combined Available Chlorine as (CAC).


Now, have a look at three types of pool shock.


Its full form is Calcium Hypochlorite. It is a strong form of chlorine. This shock controls the pH level of water & kills pollutants. It has a 10.8 pH level which is helpful to remove the acidic condition of pull water.

In a brief:

  • Contains around 65% chlorine
  • Required pre-dissolve
  • The whole process can take around 8 hours
  • Increases the amount of calcium to the water
  • Recommended to add at night


This type of pool shock is a fast-dissolving pool shock. It’s Dichloro-S-Triazinetrione pool shock. The positive side is it won’t cloud the water of the pool. But, this type of shock contains CYA which means Cyanuric acid. CYA helps to increase residual CYA which is bad for your pool.

In a brief:

  • No pre-dissolve required
  • The whole chemical process takes around 8 hours
  • Adds CYA ( Cyanuric Acid) to the water
  • Recommended to add at night


Chlorine-free pool shock works great as it oxidizes contaminants very quickly. But, the matter of concern is this type of shock is unable to kill bacteria or moss. To make your pool water more clean visibility, you can use this. 

In a brief:

  • Contains zero chlorine
  • Required no pre-dissolve
  • React very fast. Time is around 15 minutes
  • You can add both day or night time

How to shock a pool with chlorine

Before shocking a pool, be prepared with self-protection equipment. Don’t use chemicals with your hands instead of using hand gloves. We also recommend wearing eyeglasses to avoid unwanted accidents. Besides, wear the dress you won’t care if it will get damaged. Now, we are describing the shocking method step by step.


Test the water of your pool. You should use a water test kit to perform this task. This step requires verifying the pH level of your pool water. Ensure the pH is within the range mentioned on the shock container.


You have to add shock to the water. Remember, first add the water to the bucket & then, add the shock. Warm water dissolves shock faster than cold water. So, keep that in mind during the time of making a mixture. It is prohibited to mix all the shock bags in one bucket.


Use a wooden stick to dissolve the shock manually. As long as you think the shock isn’t dissolved with the water, keep going.


Circulate the water by turning on the pump. Then, carefully pick up the mixture & pour it inside of the pool. You have to pour slowly inside the pool. Some undissolved shock is present at the base of the bucket. In this circumstance, drown your bucket inside your pool water & provide it a slow wash. The residual shock will be mixed with the pool water immediately. 


Let the pump run continuously for around 6 hours. After the interval, test the water once more. Be patient until the FAC (Free Available Chlorine) level falls to 1-4 ppm. High FAC levels may hinder safe swimming.

You’re all done. Your pool is shocked successfully. Now, you can enjoy pleasant swimming.

What is a non-chlorine shock?

This is a powerful oxidizing agent in powder form, which helps to eliminate pollutants from your pool water. It is odorless. This is not a part of the sanitization process. Oxidizing agents break down oil & organics in water. As it uses the power of active oxygen in water, it doesn’t raise the chlorine level. 

If you want to get released from the torture of organic derbies, you can use it. Moreover, it won’t be helpful to destroy the spread of algae in your pool. In that case, instead of a non-chlorine shock, you’ll need a chlorinated shock.

Have your kind attention on some benefits of using non-chlorine shock.

  • It improves the efficiency of the sanitizer used in your pool. If you use an effective oxidizing agent alongside chlorinating shock, you provide access to do the best performance.
  • Sometimes your pool water may get oily. It can create bacteria & bad odors. Non-chlorine shock is capable of fighting with swimmers’ body oils, deodorant spray, dead skin cells, sweat, and so on.
  • If you want to improve the clarity of the water in your pool, you should go for a non-chlorine shock. It is effective to restore pool water into crystal clear form.

How to shock pool without chlorine

We’ve discussed the pros & cons of non-chlorine shock. The most popular non-chlorine shock is Potassium peroxymonosulfate. It was not expensive at all. Let’s know its application. It’s quite similar to the chlorinated shock.


Wear safety equipment like eyewear gloves, etc. Working with chemicals is a serious topic for your skin.


You’ve to determine the amount of non-chlorine shock in this step. One bag of shock dissolves with ten thousand gallons of water.


Make a solution with the non-chlorine shock. Some people directly pour the shock which is not recommended. To make a solution, take 5 gallons of water in a bucket & add the shock. Using more buckets reduces your time.


It may take some time to dissolve the shock in the bucket water automatically. Take a stick & mix it properly.


Through the solution of the bucket to the pool slowly. You may find some dissolved shock at the bottom of the bucket. Wash your bucket in the pool water & repeat this for all the buckets.


Wait at least 15 minutes. After the interval, you’re ready to enjoy your swim.

How to shock your pool using bleach

Bleach also contains sodium hypochlorite but the difference is in the concentration. Bleach contains diluted chlorine in its concentration at only 5-6%. Let’s see how you can shock your pool using bleach.


The pH should be controlled at first. The optimum pH is 7.2-7.8. If it’s more than 7.8, use sodium bisulfate to decrease the pH value.


Determine the level of cyanuric acid in your pool. You’ll need a test kit. The optimum measurement is 20-50 ppm.


Measure the volume of your pool to find the value of necessary bleach. If you know the water height, pool width & pool length; you can learn the value by multiplying those. 1 gallon of chlorine will raise the free chlorine level of the 30,000 gallons of pool water by 2 ppm. Mix it up in a bucket & similarly to the previous process, mix it with the stick.


Pour the bleach-mixed water into your pool. The afternoon or early evening is our recommended time schedule. After adding the bleach, turn on the pump to circulate the water. After completely getting it mixed, stop the water circulation. You’re done.

Frequently Asked Questions

We have pictured the pros & cons of pool shocking. Now, get some straight answers to the common questions.

What does pool shock kill?

Pool shock breaks apart combined chlorine & kills harmful pathogens like algae, bacteria, etc.

Can you pour shock directly into the pool?

To minimize splashing, we recommend mixing the shock with a bucket of water & then, pouring the pool water into that mixture.

Can I shock a pool with chlorine tablets?

You can add chlorine tablets but they won’t be sufficient for chlorinating pool water.

What is the difference between pool shock & granular chlorine?

Pool shock is a thing containing 65-75% of chlorine whereas granular chlorine remains in solid form.

My water is green & does not improve with shock. How do I restore the water clarity?

It may happen for the presence of metal in water & to restore the clarity, you should use oxidizing agent chlorine.

Final Words

It’s time to declare the end. I believe having a clear idea about why the pool shock is important. After going through this article properly, we believe that you have achieved much knowledge about pool shocking. If your pool spreads a bad odor, you could say it was water pollution before. But now, you can say that the combined chlorine has created & increased in your pool. After pool shock, some residual fallout could be visible at the bottom. So, you may consider cleaning the pool bottom often.

In that case, you know how to shock a pool. Moreover, you also have gained some ideas about developing clarity. As our article is full of easy instructions, it may not be problematic for readers. If you don’t get any basic asking, please read the FAQ segment again. Get rid of your algae problem by following our instructions & have a good swim.

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