Calcium Hypochlorite: A Perfect Pool Shock for Keeping Your Pool Healthy and Clean

Pool shock is a treatment done to pool water to balance it’s chemicals. You will differentiate calcium hypochlorite and sodium hypochlorite and their advantages.

Pool Shock with Calcium Hypochlorite

Have you ever heard of Calcium hypochlorite shock?

Well, it is a pool water treatment. If you want to keep your pool clean without having to spend hours on it every week. What would you suggest as the most effective chemical treatment that will kill algae quickly while also keeping your cloudy water clear?

You’ve tried everything from vinegar to chlorine tablets to nothing at all. Now you just want something simple that works well enough so you can relax and enjoy swimming again.

Calcium Hypochlorite is the better option! Calcium Hypochlorite is 20 times more potent than chlorine at fighting pathogens and reducing heavy metals like arsenic, copper, lead, mercury, nickel, and zinc.

This means you don’t need to shock your pool as often to prevent algal blooms and bacteria levels. Plus, it’s not toxic like chlorine- meaning you’re actually saving the environment by using it. Want to make sure your pool is clean and safe for everyone? Not sure how to do it? Liquid chlorine is the way to go. Read this article.

If you’re seeking a reliable and efficient way to keep your pool sterilized and clean, keep reading to know why Calcium Hypochlorite is one of the best pool sanitizers out there. 

What is Calcium Hypochlorite

Calcium Hypochlorite has been used for years to disinfect swimming pools and spas and purify water in other industrial settings where chlorine may be ineffective or problematic for other reasons (elevated pH levels or ammonia levels). 

When you add calcium hypochlorite to your pool, the chlorine interacts with the water and forms Hydrochloric Acid very rapidly. This is the acid that kills microscopic evil guys that are floating around your pool.

It makes the killing by attaching itself to the enzymes of the cells of the microbes, destroying the cell wall and rendering it ineffective.

Is Calcium Hypochlorite Safe to Use? 

The answer is yes! Calcium Hypochlorite is an FDA-approved, natural alternative that’s been used for decades. The EPA has also given it a “green” seal of approval.

This is a safe and effective way to keep your pool cleaner, healthier, and, most importantly – longer!

When Should You Use Calcium Hypochlorite to Shock Your Swimming Pool?

Calcium Hypochlorite is a powerful oxidant that can be used as a light chemical shock to treat your pool. When you use it to take care of algae, you don’t have to use it in the same quantity as traditional chlorine or bromine; this means that calcium hypochlorite will last longer and save you in expenses in the long run. 

You should also consider using calcium hypochlorite if your pool gets hot rapidly- this type of chlorine stays effective at higher temperatures than the other types available on the market.

Here are more instances on when you should use Cal hypo:

  • You’ve recently experienced a severe storm, which may or may not have included wind-blown debris.
  • Your pool has been subjected to an unusually high volume of use (like a big pool party)
  • The amount of water in your pool has dropped substantially.
  • Someone has made the mistake of thinking your swimming pool is the toilet bowl (i.e., call of nature-related mishaps)

How to Use Calcium Hypochlorite to Shock Your Swimming Pool

For every pool owner, there are no pools that are completely alike. Therefore, the particular process for applying this super-sanitizer will vary based on the size of your pool and the product you choose. However, cal hypo is easy to use, and it is difficult to go wrong with such a straightforward solution.

safety gloves and googles

First and foremost, gather the necessary supplies that you need, including:

  • Cal hypo
  • A bucket enough to carry 5 gallons
  • Safety goggles
  • Closed shoes
  • Pants
  • Long sleeve shirts
  • Gloves that are resistant to chemicals
  • Stir stick (preferably wooden)

Note: Make sure that you have donned all of the appropriate safety equipment or are easily accessible. 

shock pool with calhypo

Here are the series of steps on how you can shock your pool with calcium hypochlorite:

  • Put on your protective equipment.
  • Then, you should do TC, FC, and CC tests for your pool water. If you have hard water, please monitor your calcium levels to avoid any hardware difficulties. 
  • Next is calculating how much cal hypo you will need to add. 
  • Depending on the box, you’ll most likely discover a chart or guide that will tell you how much shock to use. You can also use your math equation.
  • After you have measured out the appropriate amount of solution, fill your bucket with about 75% of warmer water.
  • Add the Cal hypo one pound at a time
  • Mix the two ingredients by stirring your stick in circular motions.
  • Continue mixing and stop only if the sanitizer has been completely dissolved in the bucket.
  • Walk around the perimeters of your entire pool, gently and evenly dumping the mixture into the water. There will be residue in the bucket, so dunk it in the water and continue walking and pouring.
  • Swirl or mix it quickly with your stick around the inside perimeter of your pool to ensure that it gets evenly distributed throughout the water.
  • Now that you’re done with the process. We would advise you to stay out of the pool for at least 8 hours. This shouldn’t be a problem if your shocking at dawn. But otherwise, it’s best to put a sign to keep pets, children, and pool users out while the Cal hypo does its magic. 

Calcium Hypochlorite vs. Sodium Hypochlorite

Calcium Hypochlorite on Palm

Calcium hypochlorite is a chemical compound that contains calcium and chlorine. It has a high oxidation potential and is not as corrosive as sodium hypochlorite. Calcium Hypo can also be mixed with other pool chemicals to increase the oxidizing power, while sodium hypochlorite only serves to provide disinfectant properties when it oxidizes.

Sodium Hypochlorite in a Glass Bottle

This is why you’ll find Cal Hypo as the active ingredient for pool shock and sodium hypochlorite in liquid bleach. You can also use Cal Hypo to disinfect your water supply if you do not access a Chlorine Generator or a Sodium Hypochlorite solution. 

Advantages and Disadvantages of Calcium Hypochlorite

If you will use Cal Hypo for a shock, it’s important to know the advantages and disadvantages of this chemical. 

Advantages of Cal Hypo

  • Cost-effective
  • Easily available and easy to transport
  • Considered safer to use when compared with other chemicals like chlorine or sodium hypochlorite 
  • Large range of commercial applications 
  • Easy to use
  • It’s very strong and fast-acting
  • Does not need to be stored or handled in a water container with a lid. 

Disadvantages of Cal Hypo

  • It is necessary to pre-dissolve it.
  • You must apply it manually, unlike tablet forms which can drop chlorine in your pool slowly.
  • It creates momentary cloudiness in your pool.
  • Might have long-term effects when exposed to large quantities for extended periods. 
  • Toxic to aquatic life. 
  • May cause eye irritation

More Potential Advantages/Disadvantages

This Pool is Exposed to Sunlight

Depending on the present condition of your pool chemistry, here are the following points that you might either consider as advantages or disadvantages:

  • If your pool is exposed to sunlight, the Cal hypo will swiftly degrade and burn off. If you’re looking for a temporary chlorine levels boost, this is the method to employ, but you may also manually add cyanuric acid to your water…
  • Because it has a high pH, it will very certainly boost the pH water level of your pool. This can be beneficial if you happen to need to elevate your pH simultaneously, but it might be inconvenient if you don’t. Muriatic acid, on the other hand, can be used to bring the pH level back down.
  • It can improve the calcium content of your pool water. If you need to boost your calcium hardness levels, this is a good option. However, using too much calcium hardness will result in calcium scaling, which cannot be readily rectified.


As you can see, there are several factors that must be considered to administer calcium hypochlorite successfully. When you put in the effort to learn how it works and how effective it is, you can turn your pool into a safe and clean swimming environment.

Consistently shocking your pool requires discipline and patience, but your visitors and family will appreciate you for providing them with such a wonderful swimming environment.

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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