Revealed: How to Shock a Pool

Have you ever wished that your pool gets rid of the lingering algae? Did your friends complain the last time about the odor coming out of your pool? Do you want to eradicate this menace of algae once and for all?

Well, if that’s the case, you have landed at the right place. In this article, you won’t only learn how to shock a pool, but to do so at a remarkably economical price. As a result, you will succeed in your quest of getting a cleaner, user-friendly outdoor pool.

Before we shed some light on how to shock a pool, let’s take a look at some of the other queries which are associated with the shocking.

Carefully choose the time for Shocking

As far as most experts are concerned, they recommend that we shock the pool at night. This is done to help the chemical which is used for shocking. For example, chlorine is the chemical which is used most often for shocking.

In order to get the maximum results from chlorine, you need to do the task at night. The reason for this is simple: in the broad daylight, the sun eats the chlorine. Therefore, in order to save your time and money, I would recommend that you shock your pool at night.

Carry out a test for recording the chlorine demand of your pool

Although pool shocking sounds very easy, people who have actually done it believe otherwise.

The main problem which the majority of first-timers encounter in their first attempt is when, despite adding chlorine, the amount of algae remains the same in water. This happens because they haven’t tested the chlorine demand of their pool.

testing chlorine levels


Chlorine demand is actually the amount of chlorine your pool needs in order to convert all the bacteria into chloramines. These chloramines will be diffused into the air. Unless you haven’t satisfied this demand, no pool shocking chemical will come to your rescue.

Hence, before doing anything, purchase a pool water test kit from the market. While this won’t help you in shocking the pool, it will give you the chlorine demand of your pool.

Use a few protective equipment

Since you’ll be dealing with chemicals in the concentrated form, use gloves and goggles in dealing with them. Moreover, try to use worn out clothes during shocking. This is due to the fact that the chlorine granules are concentrated, and they will most probably make holes in your shirt.

How many Packets for shocking? Decide wisely

According to the standard, one packet of shock, which normally weighs 1 pound, should be enough for 10,000 gallons of water. Therefore, before going out in the market, get a raw estimate of the gallons that your pool is holding. For this purpose, you could use the pool volume calculator.

Dissolve your shock packets in water – and not the other way around!

Take a bucket, fill it with water and add the shock packet. Remember, water first – chemical last. Once you have added the shock packet into the bucket full of water, gently stir the water to dissolve the packets.

Slowly pour the Mixture into the pool

Once you have made the shock solution as per the manufacturer’s recommendations, pour it slowly into the pool. Avoid splashing or throwing the water into the pool. After you have done this, all you have got to do is to wait and let the chemical do the magic.

Different types of water – and how to select the Chemical in each case

You might have noticed that while your pool is light green, that of your friend is black green or darker in color. The difference comes from the amount of algae which has accumulated in the pool.

Therefore, before telling you how to shock the pool, it is very crucial that you choose the optimum amount of chemical in each case.

  • For Light Green Water:

If the water is light green, it means there is a very low amount of algae in your pool. Consequently, you won’t have to use extravagant amounts of chlorine to shock. Thus, 2 pounds per 10,000 gallons will do the trick.

For Light Green Water:


  • For Dark Green Water:

If the water is dark green, it means that medium amount of algae is in your water. Therefore, you will need to shock your pool thrice. For this, you’ll have to add 3 pounds of chlorine per 10,000 gallons of water.

Dark green pool water
  • For Black Green Water:

This is the worst case scenario. It means that your pool hasn’t been cleaned in ages. In other words, you will have to spend some extra bucks to shock it. Thereby, for a pool which contains black-green water, 4 pounds of chlorine are required per 10,000 gallons of water.

Black green pool water


Once you have shocked the pool, your pool water will acquire a cloudy blue color. There’s no need to worry as the appearance of this color indicates that shocking has been successful.

Different types of Chemicals you could use in Pool Shocking

As you might have noticed in your market tour, there is a myriad of chemicals available in the market. Since all of these chemicals won’t help you, below mentioned is a description of compounds with their pros and cons …

  • Calcium Hypochlorite Shock

    In case you don’t want to take any risk, calcium hypochlorite shock is a must-have for you. With all-round properties, 65% chlorine and lots of calcium, this chemical is best for almost all types of pool water. However, it comes with a caution. After you have shocked the pool with calcium hypochlorite, don’t use it for at least 8 hours. You can get it here.

  • Lithium Hypochlorite Shock

    In such a case when the water testing has revealed the presence of calcium in your pool, you don’t need to spend amount to add extra calcium to it. In such a case, go for the calcium-free, Lithium Hypochlorite shock. However, you still won’t be able to use the pool for 8 hours after adding the chemical into it. You can get it here.

  • DiChlor Shock

    If you live in a hot area, DiChlor shock might save you a lot of money. The sun oxidizes chlorine mitigating its effectiveness. Thus, in order to support chlorine, a dichlor shock could be used. You can get it here.

  • Non-Chlorine Shock

    For people who want instant results, use the non-chlorine shock for their pool. Containing a large amount of bromine, this chemical could be added to your pool at any time of the day. Since the sun won’t be able to oxidize bromine, the chemical will remain intact even in broad daylight. Moreover, after shocking the pool with bromine, you could jump into it within 15 minutes. You can get it here.

Now that we have settled different queries, let’s move on to the major part telling how to shock the pool.

How to shock your swimming pool step-by-step guide

  • Step#1: Test the water

As mentioned in the above mentioned description, the number of algae are crucial in deciding whether your pool shock will succeed or not. Therefore, before you decide on the amount of chemical, I would recommend using a water testing kit for pH testing. Before you have added any chemical, the pH will be very low.

After shocking, the pH will go high. However, in order to prevent it from being too high, test the water before starting the shock.

  • Step #2: Use a Pool Brush to scratch the algae of the walls

As you might have seen yourself, the favorite habit of algae is to cling to the walls of the pool. Therefore, in order to have the maximum effect of shocking, brush the walls of the pool to scratch algae off it. Look for areas where algae most often reside i.e. pool steps, behind ladders, crevices, and creases.


  • Step #3: Purchase a 25-Pound container of Chlorine Granules

Once you have ensured that the pH is less than 7.2, which means that the water is slightly basic, start to shock the pool with chlorine. Instead of purchasing the usual 1pound bags that are available in the market, I would recommend you to go for a 25-pound container.

As you might guess, you’ll get a lot of subsidy by buying such an amount at once. More importantly, you could be assured that your pool would not remain under shocked.

  • Step #4: Distribute the chlorine evenly over the water

The greater the surface area that you will allow the chlorine granules to function, the greater will be their rate of reaction. Consequently, fewer pounds of chlorine will oxidize more amounts of algae. Thus, after setting the filter pump on, distribute the granules of chlorine at all corners of the pool.


  • Step #5: Don’t cover the pool during shocking

If your pool is indoor, make sure to turn on all the exhaust fans. If it is outdoor, DO NOT cover it for at least 1 day. The reason for this is simple: after shocking, Nitrogen will be released from the pool in the form of a by-product. Since it is an inert gas, it will be in your best interests if you allow it to diffuse into the atmosphere.

Although there are many types of filters used in swimming pools these days, almost all of them function similarly when it comes to pool shocking. Thus, be it the DE filter, the Sand filter, or the Cartridge filter, you don’t have to make any extra effort before using them after shocking.

However, having said that make sure to backwash the filter before shocking the pool. Afterward, when filtering out the water after the shocking, make sure there are no obstructions in the way of the drain.

Keep the filter running for at least 24 hours or until the pool is clear. If you want urgent results, add a water clarifier. It will speed up the process.

Bonus Tip: If you want a visual description on how to shock a pool, check the video below:


While you might gauge from the above-mentioned description that pool shocking is a time-taking task, the best thing you could do to save time and money is to take some extra care. For example, during the season, run your filter 8 hours daily. Try to keep your pool clean by brushing and vacuuming daily. These little things will save a lot of time and money.

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