How Much Bleach To Shock A Pool? Make Swimming Safe


When you own a pool, one of the most common problems that you will probably have is the price of maintaining the water clarity and balance in the pool. You will find out that it can be pretty costly to maintain a crystal clear swimming pool. Using bleach is one of the ways how you can do it, but you need to know how much bleach you need to add to a pool and make swimming safe.

Most pool owners use chlorine as a pool sanitizing agent. You don’t need to know chemistry so well to know that chlorine breaks down bacteria. Chlorine kills microscopic organisms that are in the water and that cause the pool water to become cloudy. This is done by using their negative charge to rip through the outer membrane.

Such bacteria are dangerous and should not be in the pool. Therefore, it is important to know how much bleach you need to add to shock a pool and make swimming safe. The most popular form of chlorine that is used is liquid bleach or hypochlorous acid. In this article, we’ll talk about how to use it and how much bleach is needed to shock a pool. Let’s begin!

How Much Bleach To Shock A Pool?

So, How Much Bleach To Shock A Pool? To disinfect a surface, the CDC recommends about 5 tablespoons of regular bleach per gallon of water. For a liquid pool shock, it is preferred to dilute it at a rate of 2.5 to 3 tablespoons per gallon of water. For a 5,000-gallon pool, you need 3 cups or 24 oz of Clorox bleach to raise the chlorine level.

When we say“Shock a pool”, it refers to the process of adding chlorine to the pool water, so it can raise the “free chlorine” level. Before you start adding bleach to shock a pool, you need to know how many gallons of water your pool has. Therefore, we will explain everything in detail below so that you know exactly how much bleach you need to add.

Swimming Pool Size Bleach To Add
5,000 Gallons3 cups or 24 oz
10,000 Gallons6 cups or 48 oz
15,000 Gallons9 cups or 72 oz
20,000 Gallons12 cups or 96 oz

For those who want to know more, you can read our article, How a Bathtub Works? Plumbing & Drain System.

Adding Clorox Bleach To My Pool – Things To Know

So, how much bleach to add to the pool? The first thing you need to know before adding a Clorox bleach is the size of the pool and what is the chlorine levels of the pool. The best way to measure it is to get a Chlorine Testing Pool kit. The preferred chlorine level for the pool is around 1.0 to 3.0 ppm (parts per million), so the water is safe for everyone who wants to take a swim. Once you do the chlorine level test, you must know how many gallons your pool has so you can add the exact amount of bleach to it.

Note! Clorox Bleach is the same stuff as Liquid Chlorine just weaker by product weight.

Here is the great Youtube video where it is shown the process of adding Clorox bleach to the pool.

How To Calculate How Many Gallons Your Pool Has?

If you don’t know how many gallons your swimming pool has, just use the basic formula that we’ll give you. The formula for calculating a pool area in square feet or meters is the following:

  • Length x width x depth x 7.5 = volume (in gallons)

By multiplying the length of the pool with width and depth gives the volume in cubic feet. Since each cubic foot has 7.5 gallons of water, multiply the cubic feet of the pool by 7.5 and you will get the volume of the pool in gallons.

If you have a round pool, then you need to multiply the volume of the pool by 5.9. For the oval pool, you need to multiply it by 6.7. I hope that you know now how to calculate the pool gallons. If not, you can use the calculator below in which you just need to type the basic data and you will get the results.

Use this Swimming Pool Calculator.

Now that you know how to calculate the volume of your pool and how many gallons you have, you now need to know how much ppm you have in your pool.

How Much Bleach Do You Need For A 5000 Gallon Pool?

So, how much bleach do you put in a 5,000-gallon pool? To shock a pool with bleach or Clorox, you will need to use ¼ gallon of bleach per 5000 gallons of water to raise the level of chlorine to 5 ppm. However, if you want to bleach 1000 gallons of pool water, you’ll need (1000*½)/10000 which is equal to 0.05 gallons of bleach.

Clorox bleach is certainly the most common bleach product that is used for swimming pools. The concentration of Clorox is 5.7%, which means that if you have a 5,000-gallon pool, you’ll need to use 3 cups or 24 oz to raise the level of chlorine in the pool.

How Much Bleach Do You Need For A 10,000 Gallon Pool?

So, how much bleach do you put in a 10,000-gallon pool? To shock a pool with Clorox or bleach, you will need to use ½ gallon of bleach per 10,000 gallons of water to raise the level of chlorine to 5 ppm. To raise the chlorine level for just 2.5 ppm, it is recommended to use as much as ¼ gallon of bleach per 10,000 gallons of water.

When Do You Need To Shock A Pool?

When your pool has cloudy or green water, that means that the level of chlorine in the pool is too low and that it has fallen below the recommended value which is 1 ppm (part per million).  This usually happens when chlorine has formed chloramines, which with bacteria and other contaminants is no longer available for sanitizing. Chloramines can emit an odor, so regardless of the fact that the concentration of free chlorine is low, the pool may actually smell of chlorine.

Step-by-Step On How To Add Bleach To The Pool

Although this process is familiar to some, we will explain in 4 simple steps how to add bleach to the pool. It’s important to know how many gallons of bleach is needed to shock the pool.

Step 1: Test The pH Of Pool Water

Test The pH Of Pool Water

The first step is to test the pH of your pool water with a pH meter and to add sodium bisulfate to lower it if it’s too high. Keep in mind that if pH is above 7.8, chlorine quickly loses its effectiveness. Ideally, the pH level should be in the range of 7.2 and 7.8. If you don’t have it, you can order your pH Meter Here.    

Step 2: Measure the Cyanuric Acid Level

Measure the Cyanuric Acid Level

To check the level of Cyanuric Acid in your pool, use the Test Strips kit. The Cyanuric acid level in the pool should be between 20 and 50 ppm. If the level is too low, to raise the concentration, just add a stabilizer to the pool water. You can use the instructions on the container of the stabilizer product that you are using.

Step 3: Measure The Volume Of The Pool

Measure The Volume Of The Pool

To know how much bleach you need to add to the pool, it is necessary to calculate the volume of the pool. Just multiply the length of the pool with the width and depth, and you will get the volume in cubic feet. The 1 gallon of bleach will raise the free chlorine level by 2 ppm on the 30,000 gallons of water. To mildly shock a 30,000-gallon pool, you will need 2.5 gallons of bleach to raise the free chlorine concentration to 5 ppm.

Step 4: Add The Bleach To The Pool

Add The Bleach To The Pool

Now that you have completed the previous steps, you just need to add the bleach to the pool. Do this during the late afternoon or early evening. The best way to do this is to walk by the pool and gently pour it out (never pour it into the skimmer). Don’t forget to circulate the water for several hours after you add the bleach so that the bleach gets mixed with water completely.

Clorox Bleach Vs Pool Shock To Disinfect

Bleach is a product that can sometimes be hard to find on store shelves. So, the question “Is there some difference between swimming Pool Shock and Clorox bleach, and can they be used to pool shock?” You can use pool shock instead of Clorox bleach, but make sure to dilute it first.

The ‘chlorine’ that is in the bleach is actually sodium hypochlorite. Swimming pool shock usually has 12% sodium hypochlorite (bleach) compared to 6-8% of Clorox bleach.

With a 12% concentrate, the liquid pool shock is around 2 times stronger than Clorox bleach. The CDC suggests 5 tablespoons of normal bleach per one gallon of water to normally disinfect a surface. Therefore, when you are using a liquid pool shock, try to dilute it at a rate of around 2.5 to 3 tablespoons per gallon of water.

Why Pool Stores Don’t Recommend Bleach?

If you go to a pool store, you will find out that they do not suggest that you use normal chlorine as a bleaching agent. They will recommend you to use their products. Most pool stores are selling chlorine tablets that are combined with other chemicals, and they are released slower, which makes them last longer. While this is certainly an easier solution, stabilizing the bleach reduces the effectiveness of killing the microbes in the pool.

On the other hand, Clorox bleach is considered to be one of the most common bleach products for pools. Therefore, bleach can also be used in the pool and it is a very safe product. Clorox bleach consists of a 5.7% concentration. Keep in mind that when you add liquid bleach to a pool, it is still needed to add a little amount of stabilizer with it. This is because the sunlight can eliminate the bleach molecules in the pool if it is not added.

FAQ: People Also Ask

How Long After Putting Bleach In Pool Can You Swim?

After adding bleach to the pool it is recommended to wait somewhere between 20 min to an hour before you can safely go into the pool. If you notice calcium chloride in your pool, then you should wait around 2 hours to swim. Make sure that your chlorine levels in the pool are around 5 ppm which allows you to swim safely. You can simply test your pool chlorine levels by using a test strip.

Can I Use Bleach To Kill Algae In My Pool?

For the pool, it is needed around 6 quarts (1.5 gallons) of bleach per 10,000 gallons (37.854 liters) of water, so to kill algae, you’ll need to use around 8 quarts (2 gallons) per 10,000 gallons. If you notice that the pool water is cloudy and green, you will probably need to double the basic dosage. Be sure to stay out of the pool until the chlorine drops to safe levels.

Is Chlorine For The Pool The Same As Bleach?

The bleach unlike common pool chlorine is made up of the chemical calcium hypochlorite that is around 65% strength. Bleach that is used in homes is a liquid that has sodium hypochlorite, which is chlorine in the liquid form. On the other side, the bleach is typically only 5-6% chlorine.

Final Thoughts

In summary, the first thing you need to know before adding bleach to your pool is to know how many gallons your pool has. This is necessary so that you can use the correct amount of bleach. By using bleach you will have a beautiful pool. If you followed the steps in this article, you will for sure have a crystal clear pool without spending a lot of money.

This method of adding bleach to the pool is a cost-effective and very used method for keeping your pool safe for swimming during the summer. I hope this article has helped you and if you have any additional questions feel free to contact us or leave a comment below.

Mario

I'm the CEO and founder of Home Hacks DIY. I have been involved in home improvement since my early age. I will try to pass you my knowledge and expertise in this industry in which I have been involved for the last 10 years.

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