Best Pool Shock

Regularly shocking your pool can seem daunting, but it’s a great way to keep your pool looking clean and safe for your family to swim in.

If you’re new to the concept of shocking your pool, pool shock is essentially a high dose of chlorine that pool owners must add to their pool from time to time to keep it clear and algae-free. Pool shock kills bacteria and algae forming in the pool, which keeps the water clean and safe.

The type of shock you choose is also an important decision! Check out my top picks for pool shock choices to get an idea of the best options on the market for you right now.

Pool Shock: My Top Picks

In The Swim Chlorine Pool Shock

⭐ Best Calcium Hypochlorite Shock

This popular crystal-form pool shock is pre-portioned into small bags that include just enough shock for each treatment of your pool. The shock can be dissolved in warm water or poured directly into the pool for easy use.

Each time the shock is applied, it works quickly to kill and dissolve any bacteria and algae forming in your pool. The high potency of chlorine has visible effects, especially in a dirty or cloudy swimming pool.

The frequency of shock treatments will vary according to the conditions of your pool but should be around once a week. This product is only available in pre-portioned, 1-pound bags. In The Swim is a trustworthy and famous brand for all pool chemicals and cleaning products, so this should be a good option for most pool owners.

In The Swim Chlorine Pool Shock - 12 X 1 Pound Bags
  • 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
  • Special Shipping Information: This product may not be available for 1 or 2 day shipping due to federal regulations that require it to ship via ground...


  • The main active ingredient is 68% Calcium Hypochlorite
  • Dosage: 1 pound per 10,000 gallons
  • Available in 6, 12, or 24 count 1-pound bags


  • Pre-portioned amounts of shock eliminate the need to measure amounts before use
  • High doses of calcium hypochlorite create fast pool oxidation for quick results
  • Budget-friendly option compared to similar products


  • Not compatible with vinyl-lined pools
  • Long shipping times

Nava Chemicals StarPlus Chlorinating Shock Treatment

⭐ Best Dichlor Shock

This stabilized pool shock is a great option for clearing up any pool or spa. The high dosage of chlorine works to shock your pool quickly by getting rid of any foreign matter in the water.

The manufacturers of this stabilized pool shock guarantee that using this product will not lead to scale build-up in your pool. “Scale” refers to calcium and mineral buildup that can result from the use of certain chemicals in your pool.

This product can be used approximately once a month, but actual usage amounts will vary according to your pool’s conditions.

Nava Chemicals StarPlus 1-1301-12 Chlorinating Shock Treatment for Swimming Pools, 1-Pound, 12-Pack
  • Dichlor pool shock
  • Will not cause scale build up
  • Stabilized pool shock
  • For all pools and spas
  • One pound per 10,000 gallons


  • Dichlor stabilized shock is approximately 55.5% chlorine
  • Dosage: 1 pound per 10,000 gallons
  • Available in 12 or 24-count 1-pound bags
  • Dissolve speed is not available


  • It can be used in all types of pools and spas
  • Works as a nonharmful disinfectant and clarifier


  • A little more expensive than other similar products

In The Swim Chlorine-Free Oxidizing Pool Shock

⭐ Best Non-Chlorine Shock

This chlorine-free option for shocking your pool is a popular choice among pool owners who sanitize their pools on a weekly basis.

The composition of this oxidizing pool shock is compatible with virtually any type of sanitized pool. The main ingredient in this pool shock, potassium monopersulfate, works to reactivate inactive forms of chlorine in your pool. The process of eliminating non-sanitizing chlorine and reactivating sanitizing chlorine will help keep your pool free of algae and other dirty microbes that could create issues for you. It can be used as routine maintenance for any type of pool. It is also saltwater pool compatible and will not alter any of the other chemicals in your pool.

This chlorine-free pool shock dissolves quickly and easily so you are able to use your pool within a half-hour after using this product. If you’re unsure about how to use this type of shock, head over to my guide on non-chlorine shock.

In The Swim Chlorine-Free Pool Shock-Oxidizer - 24 x 1 Pound Bags
  • Our chlorine free pool shock-oxidizer comes in convenient 1 pound bags
  • Other applications and weekly maintenance will not affect other chemical levels.
  • Safe enough to swim right after application!
  • Use chlorine free pool shock-oxidizer on a weekly basis to shock non-living swimmer waste.
  • Dosage: 1 Pound per 10,000 gallons


  • The main ingredient is Potassium Monopersulfate
  • Dosage: 1 pound per 10,000 gallons
  • Ideally used with chlorine or bromine sanitized applications
  • Dissolves within 15 minutes


  • Usage does not affect other chemical levels
  • Can be used with any type of pool
  • Reasonably priced


  • Not the best choice for opening a very dirty or cloudy pool because of low amount of active ingredient

HTH Ultimate Shock Treatment

⭐ Best All-In-One Treatment

This ultimate shock treatment promises to do more than just clear up the algae settling in the bottom of your pool.

The amount of Calcium Hypochlorite in this product kills bacteria and algae quickly and with every use. The chemical composition also works to reduce eye irritation from the pool water and prevent the formation of calcium buildup.

This pool shock can be used in all pool types, even those with a liner, which can be an issue with other pool shock solutions that cause the liner to fade.

The Visible Blue action included in this product allows it to appear blue while in use in the water. The blue coloring lets you track the spread of the product and see for yourself that the shock treatment is at work.

HTH 52028 Ultimate Shock Treatment Swimming Pool Chlorine Cleaner, 1 lb (Pack of 6)
  • BENEFITS: Increases the chlorine level in swimming pools to kill bacteria and algae to keep your pool water clear and ready for fun all season long
  • USE: Apply directly to pool water as needed; Test pool water and shock weekly to keep free available chlorine levels between 1 and 4ppm
  • COMPATIBILITY: Effective for all swimming pool types including pools with liners and Gunite pools, and saltwater pool systems
  • FEATURES: Increases chlorine levels; Kills and prevents bacteria and algae; Reduces eye and skin irritation; Prevents stains from metals and scale;...
  • INCLUDES: Six 1-lb bag of shock treatment for your swimming pool


  • Main ingredient is 52% Calcium Hypochlorite
  • Ideally used once a week to keep the pool clean and clear
  • Dissolves within 24 hours


  • Can be used on all pool types
  • Prevents scale formation in water and reduces swimmer eye irritation
  • Blue coloring lets you see the shock in action


  • Only available in 1-pound packs of 6 or 36
  • Long shipping delays

Doheny’s Chlorine Super Shock

⭐ Best to Buy in Bulk

This effective shock treatment is ideal for the weekly cleaning of your swimming pool.

The 68% active ingredient of Calcium Hypochlorite works quickly to eliminate all harmful contaminants in your water after every use.

If you’re using it often, one of my favorite things about this shock is it’s available in a lot of bulk sizes – 6, 12, or 24 count 1-pound bags or in a 50- or 100-pound bulk bucket.

The larger amounts do not include pre-portioned 1-pound amounts, but it is an extremely cost-effective option to take care of your pool’s maintenance for multiple seasons. The reported shelf life of this product is approximately three years.

Doheny’s is also a popular and trusted provider of pool chemicals and cleaning supplies. The company has been selling pool products sine 1967.

Doheny's Chlorine Super Shock - 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
  • Cal Hypo Pool Shock for Regular Maintenance: Made of 68% calcium hypochlorite, with 65% available chlorine, regular doses of this chlorine shock...
  • 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...
  • Made in the USA: Doheny's Super Shock is manufactured and packaged in the USA


  • Main active ingredient is 68% Calcium Hypochlorite
  • Ideally used as routine maintenance
  • Dosage: 1 pound per 10,000 gallons


  • Available in bulk amounts
  • High chlorine amount is extra effective for killing bacteria and pathogens
  • Trustworthy brand


  • Shock is not pre-measured if purchased in large amounts

Clorox Pool & Spa Shock Plus

⭐ Easiest to Use

This Clorox 4-in-1 powder formula of pool shock can be poured right into your pool from the bottle on a weekly basis.

The powder not only works to clear up your pool water by killing bacteria, but it also can help improve filter performance. The product dissolves quickly in the water, making your pool safe to swim in within about 30 minutes of the application.

You can also use this product with the Clorox mobile app. The app allows you to check daily water sample results and chemical needs for your pool, so you know exactly how much shock to add.

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


  • Main ingredient is 58% Sodium Dichloro-s-triazinetrione, with 37% available chlorine
  • Dissolves within 15 minutes


  • Easy-to-use
  • Does not impact pH
  • Can be used for all pools, even vinyl


  • Lower percentage of available chlorine may make the product less effective

Recap: The Best Pool Shock

My Research Criteria

Deciding on the best pool shock for you is not an easy decision. Here are the main four criteria that went into my research and that you should consider when you’re picking up some new pool shock.

Chlorine Level

The amount of available chlorine in a pool shock product is one of the most important details to consider. Generally speaking, higher chlorine percentages will be more effective than lower for shocking your pool.

Because shocking the pool requires killing bacteria, you want to introduce a significant healthy chlorine level weekly. Using too low of a chlorine level will not be useful. But using too much chlorine in a short period could also skew the other chemicals in your pool and create additional problems.

Dissolve Speeds

Though it’s not the most critical factor, it’s worth considering how long it will take for your pool shock product to be effective.

Most high-quality shock products will begin working within 15 minutes. Several products mention that it is safe to swim in the pool within a half-hour of the application, but I would personally give it at least a few hours. Make sure to follow the manufacturer’s instructions! It could be several days before you see real results in the clarity of your water.

Stabilized vs. Unstabilized

Any pool shock that includes Sodium Dichlor will be considered a stabilized pool shock. Stabilized shock means the chlorine is protected from the sun and will not burn from the UV rays.

Unstabilized shock should only be used at night. It will dissipate too quickly during the day!

This also applies to chlorine, so be sure to read my guide on unstabilized vs. stabilized chlorine.

Long Term Effectiveness

For the best results for your pool, you’ll want to find some consistency with the products you use. Finding a shock that produces the consistent results will help you form a good swimming pool maintenance schedule.

That’s it for pool shocks! Questions? Feel free to drop me a line, always happy to help. Also, you can use my shock calculator to determine how much shock to add to your pool.

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