Top 7 Best Pool Shock Reviews in 2023

The truth is that you cannot always have a wholly algae-free and crystal clear swimming pools, spas, and hot tubs by slowly adding a little amount of chemicals. While being slow and steady might work for the tortoise in the race, for the algae, it might be counterproductive.

Bacteria and algae spread at an exponential rate, and once, they can achieve a certain spread level in your pool, controlling them becomes a lot more complicated. Therefore, the best way to avoid this is to purchase one of the best pool shocks to shock the water in your pool.

But, here’s the million-dollar question, how do you find the right product among thousands of brands out there? We’ve included a guide and a list of the best pool shocks on the market to help out.

Types of Pool Shock

There are three different types of pool shock chemicals on the market – calcium hypochlorite, potassium mono persulfate, and sodium di-chlor. They are all available in granular form or liquid form.

1. Calcium Hypochlorite

This is the most reliable and popular shock. Its upsides are dissolving quickly, and burning off with the aid of the Sun’s UV rays without increasing your pool’s cyanuric acid level.

However, you have to ensure it’s properly dissolved to avoid pinholes in your vinyl liner or bleaching the surface of your pool. Also, it alters the pH level of your swimming pool and best tipped in the evening.

2. Sodium Di-Chlor

This type is granular chlorine and dissolves a bit slowly. Unlike Calcium Hypochlorite, this type of shock lasts longer and comes with a stabilizer that raises the cyanuric acid level of the swimming pool. Plus, it is effective as either maintenance chlorine or shock treatment. Also, it’s best used in the evening.

3. Potassium Mono Persulfate

Potassium Mono Persulfate is type of shock that does not include chlorine. It works by oxidizing the water in the pool to get rid of contaminants and boost the working process of chlorine.

Unlike the other two kinds discussed above, this type can tip into your pool anytime during the day and resume swimming after a couple of minutes.

Top 7 Best Pool Shock by Consumer Ratings & Reports 

1. In The Swim 3 Inch Pool Chlorine Tablets


In The Swim 3,” Chlorine Tablets are designed to be thicker than its competitors, which allows them to dissolve slowly and protect the water for a longer time. These product 3-inch chlorine tablets are the best size for your automatic feeders or floaters.

It comes with industry-leading chlorine tablets having 90 percent stabilized chlorine for impressive sanitizing power. However, you’ll have to test your pool water weekly or bi-weekly, depending on usage to ensure your spa or pool water remains healthy and safe to use. Pool owners can utilize an OTO or DPO reagent-based water test kits, digital testing, or test strips for monitoring the spa or pool water chemistry.


  • Industry-leading chlorine
  • Slow-dissolving tablets for long-lasting protection
  • Each tablet are individually wrapped
  • Ideal size for automatic chlorine feeders or floaters
  • Potent 90 percent available stabilized chlorine


  • Many of the tablets arrived broken or crushed

2. In The Swim Chlorine Pool Shock


Another model from In The Swim brand designed to make you a happy camper by just sprinkling this unit on your pool once a week. You can also spray after a storm or heavy rain. It’s designed to kill harmful invading bacteria in your pool and prevents algae from taking over your spa or pool.

This shock comes in a dry, powdered form that quickly dissolves in water. For optimal results, sprinkle evenly on your pool. If you have a big pool requiring more than one bag of In The Swim Chlorine Pool Shock, then distribute it based on a bag basis.

Proper distribution of this unit will prevent localized build, which might result in damaging your pool. While chlorine may be suitable for pool, the concentrated amount can spell trouble. Therefore, it’s essential to spread this powdered shock around.


  • Dissolves quickly
  • Effective and powerful
  • Prevent algae and kills harmful bacteria
  • Give chlorine a quick boost


  • If concentrated, it might eat your rubber

3. Clorox Pool&Spa Shock XtraBlue


Clorox is a popular brand, and they are known for a lot of things, from swimming pool chemicals to kitchen cleaners. Given this size of the brand, their products appeal to people with budget constraints. This would explain how this brand is able to offer a powerful and effective pool shock at an economical price.

The bottles offer more control and make it easier to spread the content, unlike the bags. Also, the container can be resealed for people whose pool doesn’t need a whole bottle. While this feature may seem small, it’ll save you a lot of money.

Furthermore, it kills bacteria and algae reasonably well. But if you notice that the unit isn’t working for your pool/spa or the water looks green, check the date of expiration.


  • ¬†Well-known brand
  • Sanitize your pool reasonable well
  • Nice container for easy application


  • Check the expiration date before applying this product
  • Older chemicals are not effective

4. Clorox Pool&Spa XtraBlue Chlorinating Granules


This is an effective pool shock from the same brand, Clorox. This unit is sold in packs and easily dissolve for fast actions. This product can help prevent and kill mustard, blue, black, and green algae from forming or getting into your pool. While this unit may be hard on algae, it’s safe for swimmers.


  • Kills and prevent algae
  • Quickly dissolves
  • Long-lasting protection


  • Might leave residue on your pool

5. Aqua Chem 5-Pack Shock Xtra Blue for Swimming Pools


Aqua Chem Shock Xtra Blue for Swimming Pools comes in a pack of 5 at an affordable price. This shock is designed to kill both algae and bacteria in your pool. The unit helps create sparkling water and works with any pool type. The Aqua chem Shock Xtra Blue attenuates the odor of chlorine and reduces irritation. Besides, it does not affect the pH level of your pool’s water.


  • Leaves your pool sparkling and clean
  • Works with any pool types
  • Help kill bacteria and algae
  • Reduce odor of chlorine and eye irritation


  • Some owners got expired or about to get an expired unit

6. DryTec Calcium Hypochlorite Chlorinating Shock Treatment for Swimming Pools


This product from DryTec contains calcium hypochlorite, as its name implies and offers 65 percent more chlorine than its competitors. Even better, it is available in a single bag of 1 pound to provide convenience when using it.

On top of that, it helps kill bacteria and algae without altering the pH balance of your pool. In summary, this is a good buy for your pool.


  • High level of chlorine
  • Powerful shock
  • Support pH balance


  • It takes hours before you can swim

7. Zappit 73% Cal Hypo Pool Shock


This is a potent shock worth your buck. It’s an economical option and offers 70 percent chlorine to prevent and kill algae and bacteria in your pool. This 50-pound shock should last you the entire summer and keep your pool sanitized. If you are in the market for a strong shock, then this product is for you.


  • Very economical
  • Does not alter the pH level
  • Lasts the whole summer


  • Opening the bucket can be challenging

Factors to Consider When Purchasing a Pool Shock

No doubt, there are lots of options to choose from; however, knowing the right type of shock to go for will help narrow down your long list of options. Sadly, it may not be helpful in figuring out the nuances that break or makes a product.

Let’s take a look at some of the key factors to pay attention to when looking to purchase the best pool shock for your pool.

Dissolve Speed

Before the pool shock can be applied to the pool, it must be dissolved. Usually, this is done by most swimming pool owners in a separate bucket before pouring the dissolved shock into the pool.

Having the shock properly dissolved is important if you don’t want your pool liner bleached by the powdered shock granules.

As you can see, the speed at which the shock dissolve plays an integral role here. Fast dissolving granules allow pool owners to quickly add the solution into the water for a better efficient process. Besides, it reduces your chances of adding the un-dissolved powder to the water.

Level of Chlorine

The purpose of a pool shock is to keep the chlorine levels of your pool at a high level for a while, at least, to ensure that the sanitary of your swimming pool. Therefore, before buying any product, ensure you check the percentage of chlorine. Also, look out for its stability.

Many pool shocks on the market are not stabilized, which means that you only use them when the sun is down. This treatment has to be done overnight without the UV rays that acts as a catalyst to speed up the breakdown process.

It’s important to note that, there are pool shocks that do not include chlorine but still offer the same results – oxidizing the water to leave you with chlorine-free swimming pool.

PH Levels

Your pool water should be kept at a stable pH level, and a slight change can result in significant differences.

Let’s talk about what significant effects of changes in the pH levels can have: a low pH level can make the pool water corrosive and will damage any metal components, all pipes, or anything left in the water for long.

On the other hand, if the pH levels are high, the water becomes acid that irritates, hurts the eyes, nose, mouth, and ears of anyone having fun or relaxing in your pool.

Thus, it’s imperative for you to find a pool shock that will not have an effect on the pH level of your water. However, if you find that hard to achieve, then constant check the pH level of your pool water and bring it back to neutral after applying the shock solution.

Additives Free

As said earlier, it’ essential to ensure that whatever product you are going for has little impact on your swimming pool as much as possible.

Here’s the trouble, lots of pool shocks come with additional chemicals and compounds for effectiveness. Shocking regularly will leave your swimming pool with a lot of additive adding up real fast.

In short, using di-chlor to shock your pool means more cyanuric acid and cal hyp pool to increase the level of calcium in your water. While it’s not possible to purchase an utterly additive-free pool shock, but it’s better to buy a product with simpler options to avoid filling your pool with lots of unnecessary chemicals.

Liquid Vs. Powdered

Most pool shocks are available in the powdered form, which means you have to pre-mix before applying it into your swimming pool.

A liquid pool shock are better option for those who do not have the time or effort to pre-mix a shock. These products offer convenience since it’s already totally dissolved and can be tip straight into your pool. Sadly, there’s a downside to the liquid option, as it’s more pricey than the powdered option.


We’ve done our part and reviewer the best pool shocks on the market to keep your pool clean and free from algae and bacteria. There’s also a buying guide section to help you make the right decision. All in all, when it comes to purchasing a unit, it always comes down to personal preferences.