7 Best Pool Shocks: Calcium Hypochlorite, Sodium Di-Chlor & More

Best Pool Shock

Pool shock is a concentrated chemical that is distinguished in two prime types, chlorine-based or non-chlorine based. Clearly, it helps in either increasing or decreasing the chlorine level of the pool water.  

It can be used in the pool for many purposes but the best pool shock is the one that is safer for the users, does not cause accidents, and get dissolve inside the water pretty quickly.

In this pool shock review, we will suggest some of the major products in the market from the leading brands. We hope that our recommendations will help you in purchasing the right product.

7 Best Pool Shocks - Reviews

Product Name




Current Price

1. Clorox 33012CLX Pool Shock

Clorox 33012CLX Pool Shock

Quick action, less chlorine content, suitable for cleansing of the pool water, make water swim-ready in 15 minutes


2. Aqua Chem Xtra Blue Pool Shock

Aqua Chem Xtra Blue Pool Shock

Cleans the water and makes it contaminants-free, suitable for all pool types, does not increase water pH level


3. Doheny’s Super Pool Shock

Doheny’s Super Pool Shock

High in chlorine content, suitable for deep cleaning, best on removing bacteria and algae from the pool


4. In The Swim Chlorine Pool Shock

In The Swim Chlorine Pool Shock

Great in providing efficient cleaning, suitably priced, 1 pack of 1 lbs can treat 10000 gallons of water


5. DryTec Calcium Hypochlorite Pool Shock

DryTec Calcium Hypochlorite Pool Shock

Eliminate algae completely, great for the removal of contaminants, suitably priced, extremely efficient


6. Zappit 73% Cal Hypo Pool Shock

Zappit 73% Cal Hypo Pool Shock

High potential of cleaning the pool, treats 40000 gallons with 1 lbs, great overall quality


7. Nava Chemicals Star Plus 1-1301 Pool Shock Treatment

Nava Chemicals Star Plus 1-1301 Pool Shock Treatment

Mild shock, suitable for all pool types, great in performance, not harsh on the pool surface


1. Clorox 33012CLX Pool Shock

Editor's Rating: 4.5 out of 5 stars (4.5 / 5)

Clorox 33012CLX Pool Shock
  • Dosage: 12000 gal/lbs
  • Swim After: 15 mins

The powder-based Clorox shock for pool and spa is one of the finest products with a decent chlorine content. It does not harm the plasticity of the vinyl pools thus ranked as the best pool shock for vinyl liners.

This basically helps in maintaining the chlorine level of the pool, sanitizing it and removal of all kind of algae including blue, green, mustard and black as well. Available in easy to pour bottles, the product is quite convenient in application.   

Each portion of 1 lbs has the tendency to treat 12000 gallons of water. This is not too harsh for the vinyl pools as well because it does not bleach the pool as well.

The rapid dilution of the product in water and fast action makes the pool swim ready in 15 minutes. However, you are recommended to check the chlorine level of the water before jumping in.

This one is basically for sanitizing purpose and work quite efficiently. Also, the storage of this product is also quite convenient. But it leaves residue in the pool which has to be cleaned later.


  • Fast dissolving and make pool swim-ready in 15 minutes
  • Easy to use bottles
  • Kills all kind of algae
  • Easy to store the product


  • Leave residue inside the pool

2. Aqua Chem Xtra Blue Pool Shock

Editor's Rating: 4.4 out of 5 stars (4.4 / 5)

Aqua Chem Xtra Blue Pool Shock
  • Dosage: 12000 gal/lbs
  • Swim After: 15 mins

The Aqua Chem pool shock is suitable for all kind of pools. It does not increase the pH level of the water thus making it suitable for swimming in less than 15 minutes.

The shock will kill all kind of bacteria and algae and helps in creating sparkling water. It abolishes the odour and harmful affects of chlorine.

The chlorine is neutralized and water is suitable and safe for everyone. It does not cause any skin or eye irritation.

The shock is available at a highly affordable price and also work best to clear the cloudy water. The ingredients make the water free from all kind of contaminants.

While this product is highly suitable for your needs, the performance is not as likely as the counterparts. Also, the residue that it leaves behind makes the cartridge filters extremely messy and it becomes difficult to clean them.


  • Completely kills bacteria and algae
  • Makes the water sparkling clean
  • Eliminate the chlorine taste and odour
  • Suitable for all kind of pools


  • The residue makes it cartridge filters really messy
  • Performance is not as great

3. Doheny’s Super Pool Shock

Editor's Rating: 4.5 out of 5 stars (4.5 / 5)

Doheny’s Super Pool Shock
  • Dosage: 10000 gal/lbs
  • Swim After: 6 – 8 hours

The active ingredient of calcium hypochlorite in this model is highly efficient for eliminating all kind of pool contaminants. The product is most suitable for pool opening after a long time and has a lot of algae and substances for removal.

The heavy concentration of chlorine in the pool does a reasonable job in killing harmful bacteria. However, it is not ideal for quick swim because you have to leave it for 6-8 hours.

The shelf life of the shock is 3 – 4 years which makes it a valuable purchase. However, the storage can be a bit competitive due to harsh composition of the product.

Chlorine can harm the user so make sure to wear full clothes and gloves and add the product in a bucket first before spreading it inside the pool. Direct contact will be hazardous so you have to be careful while application.

The low-price is definitely a plus point and attracts many buyers. Just make sure that you don’t use heavy concentration of the product to avoid harm to the pool.


  • Great in removing all kind of contaminants
  • Helps in deep cleaning
  • Shelf value of 3 – 4 years


  • Heavy concentration will harm the pool
  • Direct contact with the product can cause allergies

4. In The Swim Chlorine Pool Shock

Editor's Rating: 4.3 out of 5 stars (4.3 / 5)

In The Swim Chlorine Pool Shock
  • Dosage: 10000 gal/lbs
  • Swim After: 6 – 8 hours

There is almost two-third calcium hypochlorite and 65% chlorine content which helps in providing excellent cleaning of the pool water.

A single pack of 1 lbs shock can treat 10000 gallons of water. However, this will require 6 – 8 hours treatment in order to make the water swim-ready.

The application has to be done very carefully while wearing all the safety gears such as googles and gloves. This is a great product to begin the swim for the season. You should use it after a long winter to deeply clean the pool and free it from algae, bacteria and other contaminants.

You are highly suggested to mix the shock in a bucket first before exposing it to the pool water. Direct application may cause hazardous accidents.


  • Efficient cleaning of the pool
  • Makes the water free from algae
  • Suitable for initial treatment after a long time
  • Suitably priced


  • Requires very careful application

5. DryTec Calcium Hypochlorite Pool Shock

Editor's Rating: 4.2 out of 5 stars (4.2 / 5)

DryTec Calcium Hypochlorite Pool Shock
  • Dosage: 10000 gal/lbs
  • Swim After: 6 – 8 hours

This is an aggressive pool shock with high potential to kill bacteria and eliminate all kind of algae from the pool. Also, this is one of the most valuable products because you get 24 individual packs at a highly affordable price.

The easy to use packs makes it convenient for the user to treat up to 10000 gallons of water. Plus, because of the individual packings, the storage is also easy.

The chlorine content in this product is also quite high but it become suitable for deep cleaning the pool. You can say goodbye to algae, bacteria and contaminants as long as you have this shock. Certainly, this is the best pool shock for algae.

The application has to be done very carefully. You should first add the product in a bucket and make suitable liquid formulation before evenly spreading it inside the pool.

But, just like other products in the list with high chlorine level, this one also comes with large granules that are difficult to dilute. Plus, they leave messy residue.


  • Perfect for deep cleaning the pool after long time
  • Great in killing all kind of algae  
  • Available in easy to store individual packs
  • Affordable


  • Leaves messy residue behind
  • Granules are large which makes it difficult to dissolve

6. Zappit 73% Cal Hypo Pool Shock

Editor's Rating: 4.3 out of 5 stars (4.3 / 5)

Zappit 73% Cal Hypo Pool Shock
  • Dosage: 40000 gal/lbs
  • Swim After: 6 – 8 hours

This product is known as a super shock because it contains 73% calcium hypochlorite and 70% chlorine. The combination of both these components makes it highly suitable for efficient cleaning.

One of the greatest things about this shock is that it can treat almost 40000 gallons of water in 1 lbs quantity. Well, we are highly impressed with its tendency.

After pouring the product inside the pool, you will have to leave it for 6 – 8 hours and surprise yourself with crystal clean water, the next morning. Also, to avoid any reaction with the sunlight, you are highly suggested to use the shock in the evening.

Zappit pool shock is available in 2 large air tight containers that store the product easily. The granules don’t get dissolved completely and the residue cause problem in the filter cartridge and compromise its performance.


  • Treats 40000 gallons of water
  • Extremely efficient in eliminating contaminants
  • Available in huge containers of 50 lbs
  • Comes with a plastic measuring cup


  • Granules don’t completely dissolves
  • The mess get stuck in the cartridge of the filter, making it difficult to clean the pool

Editor's Rating: 5 out of 5 stars (5 / 5)

Nava Chemicals Star Plus 1-1301 Pool Shock Treatment
  • Dosage: 10000 gal/lbs
  • Swim After: 6 – 8 hours

The Nava Chemicals treatment is a mild one and does not harm the pool or its users at all. The quick formula gets dissolved immediately, making pool swim-ready in 15 minutes.

The formula used in the making of this product is quite suitable for basic cleaning. However, you cannot expect deep cleaning with this shock.

A single pound portion of the shock can treat 10000 gallons of water. Also, if you have added more powder then needed, this one will not react in accidental way.

Available in easy to use packets, this product is convenient in usage and best to store. This is the top-rated pool shock in our list.

However, the only drawback here is that the chlorine level of the pool will remain unaffected and it has basic cleaning tendency. You will not get deep cleaning with this.


  • Suitable for all kind of pool
  • No harmful affect
  • Great in dissolving
  • Quick formula that cleanses the pool rapidly


  • Absolutely unfit for deep cleaning
  • Does not change the chlorine level of water

How to Buy the Best Pool Shocks

How to Buy Best Pool Shock

Maintenance of swimming pool require a lot of efforts and usage of different products. One of such products is a pool shock that helps in deep cleaning the pool water and maintaining the chlorine level.

Here is a quick guide on how to purchase the best pool shock:

#1. Type of Pool Shocks

The pool shocks are available in three different types. They are available in granular form which is often recognized as powdered shock.

Calcium Hypochlorite: This is the strongest category in pool shocks available in the market. This is quick in dissolving and get burnt by UV rays without increasing the pool’s cyanuric acid level.

The products are sold in regular stores as well as the swimming pool supply stores. You are advised to buy it from swimming pool supply stores because they sell authentic product.

Sodium Di-Chlor: This type of shock dissolves rather slowly. It is available in powdered form and lasts for more time in the water.  

The formula comes with a stabilizer that increases water’s cyanuric acid level. This can be considered as a shock treatment or for pool’s chlorine level maintenance.

It is best to use the shock in the evening and swimming can be resumed as soon as the chlorine level is back at normal.

Potassium Mono Persulfate: Basically, this is more like a pool water cleanser because it is based on oxygen formula that helps in removing the contaminants in the water.

It helps the chlorine to work at its best and keep the pool water oxidized.

Buying Advice: In nutshell, the best pool shock treatment is with the calcium hypoclorite. This is a little strong and require proper attention as you use but its highly effective as well.

#2. Type of Pools

There are different kind of pools installed in the households. This gives birth to the requirement of different pool shocks, individually for different pool types. You can only buy the best pool shock for the money if it is compatible with the pool type.

1. Vinyl Pool

Basically, this is a plastic form made of ethylene and chlorine and thus, polyvinyl chloride is created. The common name for this is PVC.

The material is extruded and long rolls of flexible and thin material is used to line above ground or in ground pools.   

While the pool is made of chlorine, it is important to maintain a level for the pool to retain its plasticity. Over-chlorinating will also cause bleaching of vinyl liners when chlorine sits on the bottom of the pool without dissolving.

There are three types of oxidizers that easily get dissolved in vinyl pools without causing any damage. Also, you don’t have to pre-dissolve them in a separate bucket.

Non-Chlorine Shock: This oxidizer contains 100% potassium which is simply a mixture of different salts. This is a safe option to choose for vinyl pools.

You can simply pour it in the pool and enjoy swimming right after. It takes quarter the time that chlorine takes to sanitize the pool.

Shock and Swim: In this, calcium hypochlorite is formed with high pressure compaction and granulation techniques.

As a result, extremely small granules are formed that has to be dissolved in pool water. It takes not more than 15 minutes to make water swim-ready.

Lithium Pool Shock: This kind of pool shock has cleanest burning and fastest action. They don’t bleach the vinyl liners and also leave any messy residue behind.

2. Fibreglass Pool

In the making of this pool, molded shell of fibreglass is used which is further coated with gelcoat. The surface is quite durable and less affected by chlorine.

The application has to be careful. This way, you can reduce staining and fading of fibreglass. Two types of oxidizers are used to treat the pool.

Instant Liquid Chlorine: This is basically a highly granulated form of calcium hypochlorite. While it does require pre-dissolving, it is highly safe and suitable in usage. It is best to safely pour the mixture through specially designed bottle.

Super Shock & Swim: Super shock is an advanced version of regular shock used in the pool. It has fast dissolving action with balanced pH levels and does not leave any residue.

3. Concrete Pool

The pool is made of gunite shell and covered with layer of plastic that is waterproof. The plastic is also sometimes mixed with quartz, pebble, or bead to have additional colour, strength, and texture.

The usage of oxidizers depends on the composition of the plastic layer. Some of the effective options are listed below:

Pool Shock: It is the lowly priced pool shock which has around 65% of chlorine in it. Such are among the strongest form of pool shocks. For best dispersion, you should mix it in the bucket and apply after sunset.

Assure Multi-Shock: The finest oxidizer for concrete pools is Sodium Dochlor that has added clarifiers and stabilizers. The oxidation demand is reduced and pool is protected from active molecules.

Cal-Chlor Sanitizing Granules: Well, this is the most powerful pool shock among all with 68%chlorine. It is a recommended choice for commercial users plus this is available in large packs. This is for instant application for algae and faecal incidents.

How to Shock the Pool

How to Shock the Pool

Shocking a pool seems to be quite difficult. But with the right equipment and following a right approach, you can easily shock a pool. In this section of pool shock review, we will discuss the method of shocking the pool.

Equipment Required

  • Protective eyewear
  • Protective gloves
  • Long sleeved shirt and pants
  • Close toe shoes
  • Wooden spatula (for diluting the product with water)
  • Liquid testing kit
  • Pool shock
  • 5-gallons bucket

Steps to Follow

  • Wear the protective gears before starting the process
  • Use the test kit to understand the water Total Chlorine and Free Chlorine and determine the Combined Chlorine is in the facility. This will help in determining the quantity of shock required by the pool.
  • The manufacturer of the pool shock mentions the steps to follow. Best is to follow the guide.
  • If the shock has to be dissolved in the bucket then fill 3/4th of it with clean water and add the required quantity of shock. Keep stirring with a wooden spatula till its completely dissolved.
  • While adding the shock, make sure you add one bag at a time and keep going on till you get the needed quantity
  • Then, carefully pour the mixture inside the pool water and make sure its evenly distributed. Follow the recommended wait period mentioned by the manufacturer to resume using the pool.


How often should I shock my pool?

The usage of pool shock varies with the product. But, on a general note, the pool should be treated one time in a week. However, if the usage is huge then you can shock the pool after every 3 days.

When do I shock my pool?

The swimming pool water always have immense contaminants in it. There is suntan lotion or oil, hair, hair spray or gel, cosmetics, and so much that makes your swimming experience extremely bad.

All this material in the pool often causes eye irritation and unpleasant odour. Routine sanitization is important and for that you have to use pool shock on the routine basis.

What is the best time of the day to shock my pool?

The shock material has the tendency to get burned up in direct sunlight. This is especially the case with high chlorine and calcium hypochlorite composition.

The best time to shock the pool is after the direct sun rays have left the pool side area. Technically, evening time is most suitable to shock the pool. Also, you are recommended to not to use the pool until after the water chlorine level is stable.


Finding the best pool shock becomes even competitive when there are so many options available in the market to choose from.

But we take the load off of your shoulders and give you the finest suggestions in the market. These products are great in providing decent pool cleaning and maintaining the chlorine level of the water.

You can check out the Clorox pool shock review which features one of the key products in our list. Other than that, you can check out the Nava Chemicals pool shock which is mild and highly suitable for all kind of pools.

Identically, there are various other products that you can consider buying. Happy Shopping!

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