I often hate it when I come home after some day’s travel or work to find my pool showing some shades of green. This especially hits different when all I’m craving for is a good afternoon swim. However, being a pool owner for some years, this doesn’t come as a shock – pun intended, of course. Over time, I have learned to shock my pool to keep it safe and ready for swimming.

The green color developing in the pool is evidently growing algae and bacteria. Chlorine used to disinfect the pool wears out slowly, becoming ineffective. If you are in the same fold, shocking your pool is highly recommended. However, with the hundreds of shocking options for your pool available, it can be hard identifying the right choice.

Well, I thought of rounding up some of the best pool shocking chemicals I have used and proved their effectiveness.

What is Pool Shock?

Before listing the best products, what is pool shock? New pool owners accustomed to the use of chlorine in their pools could be wondering what this is. Simply put, pool shock is the remedy you need to turn your neglected swimming pool ready for swimming. It involves adding some chemicals to eliminate any harmful bacteria, algae, and contaminants in the pool.

Pool shock works by spiking chlorine levels up to 5 times, sanitizing the water, and oxidizing the chlorine molecules. This boosts the chlorine levels in water, targets and kills growing algae and bacteria. It is recommended that you shock your pool after some weeks, especially after heavy use or following contamination events, such as storms and heavy rainfalls.

Best Overall Pool Shock

In The Swim Chlorine Pool Shock

In The Swim Chlorine Granules - Cal-Hypo Pool Shock - Fast Dissolving, Granular Calcium Hypochlorite for Sanitizing Swimming Pools - 24 X 1 Pound
5,009 Reviews
In The Swim Chlorine Granules - Cal-Hypo Pool Shock - Fast Dissolving, Granular Calcium Hypochlorite for Sanitizing Swimming Pools - 24 X 1 Pound
  • Powerful chlorine shock treatment that is great for regular maintenance.
  • Quickly eliminates algae, bacteria, and other harmful contaminants from your pool water.
  • Main active ingredient is 68% Calcium Hypochlorite (Cal-Hypo) for quick sanitizing.
  • Dosage: 1 Pound per 10,000 gallons
  • Cal-Chlor granules can be used in swimming pools, spas and hot tubs. Must pre-dissolve/dilute to prevent bleaching of the liner.

My top pick for best pool shocks is the In The Swim Chlorine Pool Shock for many reasons. This pack has twenty-four bags of chlorine shock, with each pack capable of treating up to 10,000 gallons of water. Based on this, you will have a lot of time before thinking of making another purchase. However, always know your exact pool size before pouring the shock in.

Using this pool shock is also very easy. For my concrete pool, I simply poured the treatment while walking around the outer edge. For fiberglass or vinyl pool, the manufacturer recommends dissolving the shock in a five-gallon bucket before dispersing to the water/chlorine mix. Doing this ensures that the solution doesn’t remain concentrated in one area.

The In The Swim Chlorine Pool Shock contains 65% calcium hypochlorite, making it quite effective in eliminating harmful bacteria and algae growth. It works exemplary for those who want a pool shock for regular maintenance.


  • Effective in killing bacteria and algae
  • High calcium hypochlorite concentration
  • Many bags for long usage
  • Easy application


  • Takes time to dissolve

Best Pool Shock for Above Ground Pools

Pool Essentials Shock Treatment 6 Pack

Pool Essentials Shock Treatment 6 Pack (13.4 oz Bags)
6,246 Reviews
Pool Essentials Shock Treatment 6 Pack (13.4 oz Bags)
  • Fast-dissolving pool shock
  • Clears cloudy water and removes swimmer contaminants () such as body oils, sweat, lotions and urine
  • power_source_type: Manual
  • No assembly required

I liked the Pool Essentials Shock Treatment 6 Pack due to its fast-dissolving properties. Like other high-quality pool shocks, it eliminates bacteria and algae, enabling pool owners to get clean water within a few minutes. Apart from bacteria and algae, it also eliminates other contaminants, such as lotions, sweat, urine, and oils.

As with my first product, you don’t have to assemble anything when applying the chemical. You simply pour it to your pool and wait for the magic clean.


  • Easy to use
  • Clears all contaminants
  • Fast dissolving


  • Short half-life

Best Pool Shock for Algae

Clorox Pool and Spa Shock Plus

Clorox Pool&Spa 32312CLX Shock Plus, 12-Pound, White
1,453 Reviews
Clorox Pool&Spa 32312CLX Shock Plus, 12-Pound, White
  • Easy open, easy pour bottles
  • Clears cloudy water and removes swimmer contaminants
  • 4-In-1 formula won't impact pH
  • Improves filter performance
  • Treat and Swim in 15 minutes if free chlorine is between 1 to 4 ppm

Clorox is a well-established brand with a lot of quality pool maintenance products on the market. The majority of those who have used their products are not only comfortable with the brand name but also the simplicity in which Clorox products achieve their goals. Among them is the Clorox Pool and Spa Shock Plus, which makes pool cleaning exercises resemble kitchen or bathroom cleaning.

The pool shock saves on your money while making the cleaning exercise very simple. Unlike other low-quality products, the agents don’t raise your pool PH, enabling you to get back into the pool as soon as possible. Like myself, I am sure most pool owners prefer pool cleaning chemicals that are easy to use. As for the Clorox Pool and Spa Shock Plus, you simply have to pour them directly into any type of pool.

Probably what I should consider a feature highlight of this agent is that each bottle can treat approximately 12,000 gallons of water. If your pool is smaller than this, you can use it severally.


  • Kills bacteria and algae
  • Doesn’t raise pool PH
  • Short period of action


  • Not sold in bulk packages

Best Fast Acting Pool Shock

Doheny’s Super Pool Shock  

Doheny's Chlorine Super Shock | 100% Professional-Grade | Quickly Dissolving & Fast-Acting Granular Pool Sanitizing Treatment | Highly-Concentrated 68% Calcium Hypochlorite | 1 LB Treats 10,000 Gallons | Made In The USA | 24 x 1 LB Bags
945 Reviews
Doheny's Chlorine Super Shock | 100% Professional-Grade | Quickly Dissolving & Fast-Acting Granular Pool Sanitizing Treatment | Highly-Concentrated 68% Calcium Hypochlorite | 1 LB Treats 10,000 Gallons | Made In The USA | 24 x 1 LB Bags
  • Fast Acting Pool Shock Treatment: Quickly boost the chlorine levels in your pool to remove algae and other contaminants for crystal clear pool water
  • Pro-Grade Cal Hypo Pool Shock for Regular Maintenance: Made of 68% calcium hypochlorite, with 65% available chlorine, regular doses of this chlorine shock treatment keep your pool clear all season long
  • Easy to Use: Each pound of chlorine shock comes in its own easy-to-use bag for quick, measure-free use
  • How to Use: Use one 1lb bag of Super Shock per 10,000 gallons of water. Spring openings and pools that have extensive algae blooms may require 2-3 doses to properly treat and sanitize
  • Made in the USA: Doheny's Super Shock is manufactured and packaged in the USA

If you are on the market for a product that doesn’t mess around, I recommend the Doheny’s Super Pool Shock. It is a super shock treatment formula with 68% calcium hypochlorite and available in twenty-four bags. If you have a large pool, you can place a commercial order, which comes in bulk.

The chlorine levels of this pool shock are more potent but safe for conducting regular maintenance. As with other treatments mentioned above, it is an excellent choice for removing algae, harmful bacteria, and other contaminants. Treatment directions recommend the use of one pound for every 10,000 gallons.


  • Affordable pool shock
  • Safe for regular maintenance
  • Sold in bulk


  • Takes some time to dissolve

Types of Pool Shock

Even with the best products mentioned above, I am sure the various types of pool shock available on the market might confuse both new and experienced pool owners. As such, below are the three different types of pool shock you will likely come across.

  • Calcium hypochlorite – is the popular and strongest pool shock available on the market. Pool shock made from calcium hypochlorite dissolves easily and burns off with sun rays without destabilizing cyanuric acid levels in the pool. However, it is recommended that you dilute this shock with water before adding to your pool. Also, since it increases the pool’s PH, consider using it in the evening and resume swimming once PH has stabilized.
  • Sodium Di-Chor – pool shock made from Sodium Di-Chor dissolve slowly and available in powder form. They can be used as shock treatment or maintenance chlorine. It also increases PH levels and should be used in the evening.
  • Potassium Mono Persulfate – unlike the other two, this shock has oxygen and no chlorine. It focuses on oxidizing the pool and eliminates contaminants, allowing chlorine to function better.

Is Chlorine and Shock the Same Thing?

Simply put, go for a shock if you want to shock your swimming pool. Shock is highly concentrated chlorine that increases chlorine levels quickly. Chlorine, on the other hand, is a normal disinfectant. It primarily keeps your pool water healthy, safe, and clear.

How Long Do You Have To Wait To Swim After You Shock a Pool?

The time-lapse after shocking your pool before it becomes ready depends on the agent’s dissolve speed. Different shocking agents have different dissolve speeds. Therefore, observe manufacturer’s directions indicated on your pool shock of choice.

What is the Best Type of Pool Shock?

Settling on the best type of pool shock comes down to your goals and objectives. For instance, I usually use pool shock to fight growing algae. For this situation, I will use a different pool shock compared to someone who wants to shock a pool with bromine as its disinfectant. Also, if you want to shock your pool regularly, there are specific shock agents to use.

The Bottom Line

Shocking your swimming pool is a necessity, and you should find the best pool shock for this purpose. Doing this makes your swimming sessions safe, free from algae and bacteria. As you can see, choosing the best pool shock is not difficult. Even with the many options available, consider the specifics to find one that suits your pool. When you find an appropriate shock for your pool, stock them up as they are relatively cheaper when bought in bulk.