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Have you ever felt a hard smell from your pool? What are your thoughts? Is it chlorine or other chemicals?


No, it is not chlorine. Actually, it is the chloramines, which is for the contaminants in water and the absence of free chlorine to make the pool germ free. It is the consequence of the erroneous cleaning of the pool. When chlorine incorporates with other elements (like oil, sweat, urine) in the pool, then chloramines form. On the other hand, it may add the irritability to the eyes and skin.


To avoid these problems you have to learn how to shock a pool correctly. If you are a new owner of a pool, then don’t have to be stressed about the cleaning procedure with the chemical. You will undoubtedly be overcome the fear and be a regular user of the chemical or shocks. You will have to know about how to treat pool water for the first time. You will face number of questions in terms of pool water cleaning. What does it mean to shock a pool? How long does it take to shock a pool? How to put chemicals in pool for first time? How long after shocking pool will it clear up? How often should you put chlorine in the pool? How much does shock for a pool cost? There is no limit of questions your mind will search for results.


Know about a Pool Shock

You now of course thinking about “What does it mean to shock a pool?”. “Shocking” is a vital task among the pool maintenance procedure. The process means adding the chlorine or other chemicals to the pool water to fix the balance of chlorine the germs, algae, combined chlorine are destroyed by free chlorine. The chlorine or other chemical used for the shocking process is the Pool Shock.


You have to know the difference between the free chlorine and combined chlorine so that you cannot confuse yourself. The whole thing is popular as pool shocking 101.


Pool Shocking 101

Free Chlorine:

It is the part of a chemical that is used for cleaning and sanitizing your pool water. There is a limit. You have to keep the level of FC one to the third part per million. Only then it can do the best job on your pool.


Combined Chlorine:

It issued previously on the pool and remained in the pool. But it loses its power to disinfect the water. So never allow the level of CC to .2 PPM.


Total Chlorine:

Genuinely, the simple math- the total sum of FC and CC. You can have the test kits available in the market to get the amount or level of these chemicals in the pool.


Breakpoint Chlorination:

Try to level the FC higher than the combined chlorine to destroy the chloramines. Always remember that you must add FC about ten times to the CC to balance the level of good chemicals to harmful chemicals. Every time you shock your pool, try to have the breakpoint. Otherwise, your pool will be left with replacing old and polluted water totally. You can do nothing if you do not check it regularly.


Why you Opt to Shock a Pool?

Shocking is a crucial task to do. It doesn’t matter if you install the pool recently. You have to sanitize the water must. The betterment and well being depend on the pool sanitization when the whole family dives down the pool. The living organism can harm you at the maximum level. Hence, the reasons for shocking your pool are:


  • You cannot imagine that the swimming pools are continually polluting with sweat, oils, germs, urine, and so many uneven organisms. These can be cleared by shocking the water.
  • Sunshine can break your chlorine, and it can lose up to 5 ppm chlorine.
  • Heavy rain and storms also damage the sanitization of the water, so after these incidents, a proper sanitization is needed.


How to Shock a Pool with 6 Steps

Step 1: Choose the Chemicals

At first, you have to choose the perfect shock chemical according to the test results of chlorine and other chemicals in your pool water. There are lots of available shock products in the market. You have to choose according to the types of chemicals and the quality of the product.


Step 2: Prepare the Chemicals

After choosing the shock, you have to prepare the chemical with the manufacturers’ instructions label and maintain the instructions properly. Some shocks can be in the form of tablets and some in liquid, so the quantity of measurement and ways of applying depends on the instructions.


For example, the granular shock should be poured into 5 gallons of water before pouring down to pool water. On the other hand, you can pour lithium hypochlorite directly into pool water.


Step 3: Shock the pool

The first question is, how long does it take to shock a pool? After preparing the chemicals to pour it to the pool water and turn on the filter and pump to spread the whole chemicals all over the pool. Or you can evenly circulate the chemicals in the pool water. If the chemical is in tablet forms, you can use the dispenser or floater to move the chemical all over the pool.


Step 4: Let the Shock do its work

After this, you have to leave the shock in the pool according to the instruction of the chemical purchased. You might think, how long after shocking pool can I swim or how long after shocking pool is it safe to swim. But if it is suggested not to get down the pool water within overnight, then you should maintain it properly. The maximum time that you should take to shock the pool is written too in the shock instruction.


Step 5: Check the Chemical Level of the Pool Water

After all the procedures are done, the pool water must be checked whether the chlorine or other chemical levels, alkalinity, hardness, etc. are in the correct level or not. You have to ensure that all the levels in the pool water should be in a comfort zone to dive into the pool.


Checking the pH level is very important. If the level of pH is over 8, then it becomes extremely harmful. You have to work for it within the score of pH is around 7 so that it doesn’t go higher.


Step 6: Final Filtration System

To confirm the best sanitization, you have to provide a final filtration system in the pool to get rid of all the germs. You should run the filter for at least 24 hours to have the best performance.


When to Shock a Pool

  • Don’t wait to let your pool reach the worst position, which incurs more cost and needs more time or even needs draining the pool.
  • The overgrowth of the algae makes the water cloudy, and this would harm your pool immensely. So you have to shock the pool once a week to get rid of the algae and other contaminants and prevent pollution.
  • You have known the free and combined chlorine in the beginning of the article. You should also add the knowledge that the free chlorine should be up at 3ppm. Below 3 ppm chlorine is much harmful for the sanitization of the pool.
  • Don’t think that this is the first diving into your pool; you just installed it today, so don’t need any shock. You must shock your pool before getting down the pool for the first time.
  • Moreover, you have to cover up the pool before the winter. So try to maintain this in a clear position during covering time. Don’t let the germ grow under the cover.
  • Massive storm and rain cut down the chlorine in your pool. So after these incidents, you have to shock the pool to prevent any types of water-born disease.
  • If your children have a pool party recently in your home, then the pool must be shocked immediate after the party. Don’t let them step into the pools as it would be harmful for them.


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Different Types of Pool Shock

In the market, there are a variety of chemicals of varying quantity and levels are available. You can choose the products according to your necessity.

Calcium Hypochlorite



Calcium hypochlorite is one of the affordable, accessible, and popular chemicals for shocking the pool and disinfecting the water. It is called cal hypo too.



  • It dissolves more promptly than Calcium hypochlorite. So, there is no need to dissolve at the time before pouring it at the pool water. They can mix this directly to the pool water.
  • Most chlorine products, including Lithium Hypochlorite, contains 35% chlorine.
  • You have to wait 8 hours like the previous chemical before starting swimming.
  • Using in dark is more beneficial.
  • It is poisonous for aquatic life, so don’t through the disposed water where aquatic life can be possible to live.
  • There may be a shortage of the Lithium Hypochlorite for extending price, and it is also used to make lithium battery in a great deal, so can experience the lack of this chemical for shocking in the supply market.


Calcium Hypochlorite  If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 10/29/2019

Sodium Dichlor



Sodium Dichlor shock is much easier to use and dissolve in a longer time than Calcium hypochlorite. The actual name of this is quite long as sodium dichloro-s-triazinetrione or dichloroisocyanuric acid.



  • Most chlorine products, including Sodium Dichlor, contains 35% chlorine.
  • Depending on the brand’s instruction, you may add it with water to dissolve before some time ahead of pouring to pool or directly add to the water.
  • It adds cyanuric acid with water for every ppm of Free Chlorine.
  • Use it after dark time for the best performance.
  • Wait for 8 hours to swim after the usage of the chemical.


Sodium Dichlor  If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 10/29/2019

Potassium Peroxymonosulfate



It is a non-chlorine shock. It works faster and costs less than the previous chemicals.


  • It is oxygen-based instead of chlorine-based.
  • It works by oxidizing the pool and thus accelerates the chlorine level.
  • You can swim immediately after the treatment, but 15 minutes is the least time to wait if you wish.
  • You can add the chemical directly to the pool water.
  • Remember that it doesn’t work as an algaecide.


Potassium Peroxymonosulfate   If you click this link and make a purchase, we earn a commission at no additional cost to you. Last Updated: 10/29/2019

Some Tips for Shocking and Preserving the Chemical

  • Always remember all of these are toxic chemicals and may blast if you cannot correctly handle those. Follow some tips while using those products.
  • Calcium hypochlorite may take out a minimal amount of chlorine gas occasionally. So, put on the protective gears like goggles & chemical resistant gloves to prevent skin irritation and eye irritation.
  • All the stated chemicals are different from one another. So never try to mix this chemical with one another and never try to do any home experiment as your home is not a lab. Always add the products separately.
  • It is better to wear a dust mask as the smell of chlorine gas can cause lung or throat irritation. Don’t be too close to the boxes.
  • Don’t open several containers at a time, even if you think you will need all. Always make one box empty then go for other ones.
  • Remember to follow the instructions stated in the bottle. Each brand is different from one another. If it says to dissolve before adding to the pool, then do this.
  • You may keep the pool uncovered until the average level of chlorine. You have to ensure that the chlorine level is less than 3PPM.
  • Windy days are not perfect for shocking. This can blow the shock to your eye and body.
  • After shocking the pool, try to clean every pool accessories with cleanser. Shock the pool once per week. After shocking, you can brush the pool ground to get rid of any residuals.


Frequently Asked Questions for how to shock a pool


What time of day is best to shock a pool?

Regularly you may wash your pool with shock in any time of the day. But it is recommended to use after dusk or in dark times. Moreover, the shocking can be done entirely in the overnight. So you may get some more time to get yourself free to jump in the pool to swim.


Additionally, the harmful UV rays of the sunburn the chlorine and damage the effectiveness in a general level, so sunlight is not beneficial for the shocking of the pool.


Are Shock and chlorine the same thing?

Chlorine is an effective way of disinfecting the pool. Shock products always include the chlorine chemical, and in fact, significant of the shock products include chemicals. But there are some shocks too which have different chemical than chlorine or chlorine less. These can affect the pool with sanitization but not like chlorine.


Does a shocking pool raise chlorine?

Yes, it raises the free chlorine. But it is not harmful. In fact, different shocks have a various amount of chlorine left in. So this will increase the chlorine in a different level. Shock increases the pH level of the pool water along with the increased level of free chlorine too. The level of chlorine shock keeps a balance between the free and combined chlorine. Thus shock maintains the sanity of the pool.


Will Shock clear a cloudy pool?

Obviously, a significant task of shock is to clear the cloudy pool. The dose of chlorine and chlorine-free treatment both can make the murky water clear in this term. The cloudy tendency occurs for the bacteria, algaecide, and other microorganisms. Shock can clear all of these and make the water crystal clear.


How much shock does it take to kill algae?

It usually is instructed in the container of every product that how much should be needed and how much time you should wait. Usually 1 pound of shock may be enough for per 10000 gallons of water and takes 10 hours to shock the pool. It is the estimation in a general manner.


Can I shock my pool in the rain?

It is necessary to shock the pool after heavy rain. Shocking in the rain doesn’t bring any good thing but you must shock the pool after rain. Rain may bring some uneven elements and algaecide in the pool water, so the pool needs a shock every time after heavy rain.


What’s better liquid or powder shock?

There is not much variety in the activity. Liquid shock is of fewer prices than powder shock, and it comes in refilling options. Liquid forms are already in liquid form, so you do not have to mix with the water. You can pour it into water directly.

How long after shocking a pool before swimming?

The answer depends on the conditions whethere you have used chlorine or not. If you used chlorine, then you will have to wait at least 12 to 24c hours to swim safely. On the other hand, if you chose the non-chlorine shocking process, then you will feel to jump just after completing the shocking process.

How much chlorine should I add to my pool?

There are few issues to cover the answer of this question. The filter machine is related with the chlorine amount. If you want to add chlorine when the filter is running, then the amount will be litte bit differ to if the filter is not running. More over, the amount is mostly depends on the size of the pool. The chlrine amount will be needed around 52-1-4 oz of liqued chlorine per 1,000 gallon of water. The chlorine level should be between 5 to 10 Parts per million(ppm) with this chlorine amount.

How much liquid chlorine to shock a pool with algae?

The general equation about the amount of chlorine to shock a pool with algae is about 30 Parts per million(ppm). If we assume that your pool is clean, clear and already pH have been adjusted, then you can add the that amoun of chlorine. Usually, there are pool shock packages state addition of 1 lb. shock in every 10,000 pool water gallons.


Final Words

I think I have been able to make you understand the mathematics of when, why, how, and how many times you need to shock your pool. Starting with the measurement to the time table, all you need to be a little bit analyzer. Then you can make the overall shocking and cleaning task regularly with the best performance and with no more cloudy water.


Don’t take stress about the system; you may hesitate to do this for the very first time, but the more you shock the pool, the more you will be expert in shocking the pool. Swim happily in the germ-free clear water.

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