9 Best Pool Shocks | March 2017

We spent 26 hours on research, videography, and editing, to review the top picks for this wiki. Often better at removing algae and bacteria than simple chlorine, pool shocks can also help to maintain pH balance and reduce chlorine odors. Keep your pool sparkling with something from our selection. They also work well as a treatment for the beginning and end of swimming season. Skip to the best pool shock on Amazon.
9 Best Pool Shocks | March 2017

Overall Rank: 9
Best Mid-Range
Overall Rank: 1
Best High-End
Overall Rank: 2
Best Inexpensive
The Clorox 32012CLX is packaged in convenient bottles that make treating a breeze. Just twist off the lid, pour in what you need, and close the bottle until next time. As an added benefit, it won't affect your pool's pH levels.
The HTH 51424 removes chloramines from the pool water, which cause eye irritation and strong odors, by adding free available chlorine. It also comes in a 30-pack for under $80, which is a great value.
The Kem-Tek 26449048231 is great because it allows you to start swimming after just fifteen minutes, and it even reduces your pool's other chemical needs to keep the water clean and balanced, so it saves you money.
BioGuard Burnout3 is a high-powered formula that is specifically designed to be used on any type of pool without damage, even if you have a vinyl liner. It is also compatible with bromine sanitizers.
  • dose is 1 pound per 10,000 gallons
  • destroys organic contaminants
  • water must be circulating when adding
Brand BioGuard
Model BIO22808
Weight 12.5 pounds
DryTec 1-1901-24 is an extra-strength start-up and maintenance option that improves the appearance of your pool by removing and preventing algae growth. It provides a super-fast acting chlorine boost using 68% calcium hypochlorite.
  • restores crystal clarity
  • controls cyanuric acid levels
  • has a very strong smell
Brand DryTec
Model 1-1901-24
Weight 26.5 pounds
Aqua Chem Xtra Blue is ideal for periodic shocks when you need to get your pool back in shape after letting it go for a while. It does an excellent job of killing bacteria and algae, but doesn't cost a fortune.
  • will not increase pool's ph level
  • just walk around the edge and pour
  • ready to swim after 15 minutes
Brand Aqua Chem
Model 12101AQU
Weight 5.5 pounds
Doheny's Super 7701 features calcium-hypochlorite as the active ingredient to help clear even the most contaminated pools, and each bag has a 2-3 year shelf life, so they can store in your shed throughout the winter.
  • ok to use in salt or freshwater pools
  • one bag treats up to 10,000 gallons
  • no measuring is required for application
Brand Doheny's
Model 7701
Weight pending
The Pool Essentials 25556ESS can be applied through the skimmer or put directly into the deep end of the pool, and it will start to work within a few minutes. It's a great economical way to get your pool water crystal clear.
  • ideal for all pool types
  • only need to apply once per week
  • reduces chlorine odor
Brand Pool Essentials
Model 25556ESS
Weight 6.6 pounds
Nava Dichlor is perfect to use when you need a quick chlorine dose, but want to get back in the pool without waiting days. It is also ideal for routine use throughout the pool season with a strong 56% available chlorine.
  • it is a ph-neutral formula
  • does not require pre-mixing
  • will not bleach your vinyl liner
Brand Nava Chemicals
Model 1-1301-24
Weight 26.8 pounds

What Is Pool Shock And Why Is It Needed

Pool shock is a concentrated chemical that can either be chlorine or non-chlorine based. It is used to increase free chlorine levels in your pool thereby decreasing combined chlorine. Combined chlorine or inactive chlorine is responsible for the skin irritation, red-eye and chlorine smell that people experience in some swimming pools. It is formed when the available chlorine you add to your pool in the form of sanitizer combines with organic compounds after it breaks them down and kills them. Once it has combined with the dead organic matter, it becomes inactive and is known as chloramine. The only way to remove combined chlorine is by adding excess free chlorine, which breaks apart the chloramine molecules and oxidizes it.

Without proper swimming pool sanitation, pools would quickly become filled with harmful bacteria that could cause swimmers to become sick. In addition to regularly adding chlorine or another sanitizer, pools must be shocked periodically to keep them clean and safe for swimming. The more often a pool is used, the more often it must be shocked. This is because the majority of the organic matter that renders free chlorine inactive comes from bathers. It can be in the form of sunscreen, dead skin cells, and sweat. Additional organic matter comes from leaves and dirt that enters your pool from the environment.

Adding pool shock gives your regularly used sanitizer a boost when levels are running low. Shocking a pool is also a great way to help establish correct levels of free chlorine in a newly filled swimming pool or one that is being readied for the summer after winter time neglect.

Types Of Pool Shock

Pool shocks can be chlorine or non-chlorine-based. Chlorine-based pool shocks include calcium hypochlorite, commonly referred to as Cal-Hypo, Lithium Hypochlorite, and dichloroisocyanuric acid, more commonly referred to as Di-Chlor. Non-chlorine-based pool shock is made from potassium monopersulfate.

Cal-Hypo is the most commonly used pool shock in home pools and is also the most powerful in terms of oxidation. Its main ingredient is calcium hypochlorite, and it is available in different concentrations, usually in the 65% to 75% range. There are also Cal-Hypo pool shocks advertised as allowing you to begin swimming within 15 minutes after use. This is because these products typically contain just 47% calcium hypchlorite, which may be enough to allow swimming without irritation, but is often not enough to effectively destroy all bacteria and chloramine molecules. Cal-Hypo will add both calcium and chlorine to your pool, so if your calcium hardiness is already high, it might be best to consider another shock option.

Lithium hypochlorite pool shocks are one of the best options, but are often overlooked by pool owners because of their higher cost. It is a completely soluble fine granular that dissolves instantly in water. Instead of incorporating a calcium filler like Hypo-Cal, it utilizes lithium. The standard formula contains 29% lithium hypochlorite and 35% free chlorine. It can be used in all pool types, including those with vinyl liners, leaves no binder residues, and allows you to begin swimming immediately after use.

Di-Chlor also dissolves rapidly and can safely be used in vinyl-lined pools. It is less costly than lithium hypochlorite, but more costly than Hypo-Cal. Instead of calcium or lithium, it makes use of cyanuric acid. The use of cynauric acid is a double-edged sword. On one hand, it prevents chlorine from quickly dissipating in direct sunlight, but over time excessive use can cause a buildup which limits chlorine's effectiveness.

Potassium monopersulfate non-chlorine pool shocks are not as powerful as chlorine-based products, but they are a good alternative to those worried about the harmful effects of excessive chlorine use. Instead of adding additional chlorine to a pool, potassium monopersulfate oxidizes the organic matter so the current chlorine in your pool can do its job more effectively. They also help remove cloudiness from a pool's water. Potassium monopersulfate pool shocks are pH neutral, calcium-free, and allow you to swim immediately after use.

How To Shock A Pool

When shocking a pool, it is important that you take the necessary safety precautions to avoid injuring yourself or damaging your pool. Wear safety gloves to protect your hands and glasses to protect your eyes.

The first step is to fill a five gallon bucket with water. Always add pool shock to water, never the other way around. If you add the pool shock to the bucket first, you run the risk of it splashing onto you as you fill the bucket with water. Stir the pool shock around the bucket and agitate the water to dissolve the shock granules. Once it is completely dissolved, you can begin adding the mixture to your pool water.

With the filter running, slowly pour the shock and water mixture into your pool water directly in front of the pump's return line fitting. This will help to circulate the shock around the pool and ensure that it doesn't settle onto the bottom. Never pour it directly into the skimmer.

When you have about 25% of the shock and water mixture left in the bucket, stop pouring it into the pool and add more water to top of the bucket. This will help dissolve any shock granules which did not fully dissolve the first time. If you see any granules settling on your pool floor, take out your pool brush and sweep them around to help them dissolve. If left on the pool floor they can damage it and cause bleaching.

Wiki Statistics and Editorial Log
Paid Placements

Revision History

Thanks for reading the fine print. About the Wiki: We don't accept sponsorships, free goods, samples, promotional products, or other benefits from any of the product brands featured on this page. For our full ranking methodology, please read 'about this wiki', linked below. The Wiki is a participant in associate programs from Amazon, Walmart, Ebay, Target, and others, and may earn advertising fees when you use our links to these websites. These fees will not increase your purchase price, which will be the same as any direct visitor to the merchant’s website. If you believe that your product should be included in this review, you may contact us, but we cannot guarantee a response, even if you send us flowers.

Last updated: 03/25/2017 | Authorship Information