The Many Types of Pool Shock

Shock, Shock, Shock!

Pool shock treatments are essential when opening your pool in the spring, along with pool maintenance during the swimming season. Also known as granular chlorine or powdered chlorine, pool shock can be used to kill algae, remove bacteria and other micro-contaminants, and is also used when chlorine is low and needs a quick boost.

The main reason to shock your pool is to break apart the chloramine molecule, which is what turns eyes red, and gives a pool a strong chlorine smell.

How Often should I shock? Many people “shock” their pool, or superchlorinate, once per week. This may not be necessary, unless you have high bather loads, algae or chloramine levels greater than 0.3ppm. A DPD test kit will help you calculate chloramine levels in your pool. If all is well, it may be advisable to shock monthly, to ensure that the water remains sanitary.

When should I shock? It is best to shock at night for a couple of reasons a) for most shocks, you can’t swim for about 8-10 hours after shocking, so it’s best to do the shocking treatment when you’re done swimming for the day b) the sun can eat up the shock because it is not stabilized, so it’s best to shock when it the sun isn’t out for maximum performance.

How do I shock my pool? First thing, you need to know your pool size, in gallons. If you don’t know this, you can find above ground pool gallon charts online. For in ground pools, the formula is L x W x Avg Depth x 7.5. Next, read the package label, to determine how much shock to add for your pool size. Most labels will advise you to pour the shock into a bucket full of water, stir to dissolve, and then pour the “shock water” from the bucket into the pool. Always use full bags, and distribute the shock evenly around the pool.

What about pool shock safety? I’m glad you asked, here’s some tips for handling this volatile pool chemical.

  • Never mix shock with any other shock or any other type of chemical.
  • Always use the entire bag, don’t leave half full bags of shock.
  • If broadcasting your shock over the pool, make sure you are up-wind!
  • Always add shock to water, not the other way around.

There are many different types of pool shock to choose from. Here is some helpful information and tips about the different kinds of pool shock.

Pool Shock

InTheSwim pool shockIn The Swim Pool Shock is used at a dosage of 1lb per 10,000 gallons. If you have algae in your pool, first use the shock to kill the algae at a dosage of 2lbs per 10,000 gallons. To disperse the shock into your pool, you need to dissolve the shock in a bucket of water then walk around the pool and pour it in. The reason dissolving the shock is recommended is so that the shock does not bleach your liner, or cause cloudy water in the pool. In The Swim Pool Shock is made up of 68% calcium hypochlorite, also called Cal-Hypo, and is a non-stabilized pool shock.

Super Pool Shock

buy super-pool-shockIn The Swim Super Pool Shock is a more concentrated version of our Cal-Hypo pool shock. It contains 73% calcium hypochlorite, and is also a non-stabilized shock, containing no cyanuric acid to shield it from the sun. The dosage of Super Pool Shock is 1lb per 10,000 gallons. If you are trying to kill algae it is recommended to shock 2lbs per 14,000 gallons until the algae is dead and the water takes on a grayish-blue color. Also, with Super Pool Shock it is best to dilute it in a bucket of water before broadcasting it around the pool; to prevent liner staining and cloudy water.

Chlorine-Free Pool Shock

buy chlorine free pool shock, non chlor shockNon-Chlorine pool shock is completely free of chlorine and is safe to use with chlorine and bromine pools. Don’t use Chlorine-Free shock if you use a Biguanide system, like Baquacil, or Splashies. No-Chlor shock burns off dead chlorine cells to increase the free chlorine count in your pool water. Since it does not contain any harsh chemicals it is completely safe to swim after adding the shock! Chlorine free pool shock is added at a dosage of 1lb per 10,000 gallons. Again, it is best this is dissolved in a bucket before dispersing the shock in your pool. Our non-chlorine shock is made up of 43% Potassium Monopersulfate.

Lithium Pool Shock

buy lithium poolshockLithium pool shock is a completely soluble premium granular chlorine that produces excellent chlorination. Lithium pool shock is ideal for use on hot days and is perfect for vinyl liner and fiberglass pools. It will not bleach/stain your liner, or cause cloudy water. Lithium pool shock is used at a dosage of 1lb per 12,000 gallons. When shocking your pool, it is best to dissolve the shock into a bucket of water before pouring it in your pool. Clean burning, with no binder residues. Lithium Shock is made of 35% available chlorine, and 29% lithium hypochlorite.

Assure Multishock

buy assure multi shockAssure Multishock is relatively new to the market but is getting amazing reviews. This shock is used to kill harmful bacteria, aids in algae control and help keep the pool clean and clear. Assure Multishock removes organic waste, which produces crystal clear water. This shock also replenishes Assure Conditioner that is lost due to backwashing and splash out. This shock is used at a dosage of 1lb per 13,000 gallons. You should dissolve the shock in a bucket of water before adding it to your pool. It is best to wait 8-10 hours before swimming after the use of this product. Assure multishock is made up of a stabilized form of 47% calcium hypochlorite.

HTH Sock It (Shock and Swim)

buy HTH Sock ItHTH Sock-It is a powerful yet safe shocks to use in your swimming pool. This will help control and kill algae. This product will also make your water feel softer and will polish dull looking water. It does contain 45% calcium hypochlorite, but is completely safe to swim after dispersing in your pool. It is recommended that this shock be dissolved into a bucket of water before being added to your pool. The dosage for HTH shock is flexible; it ranges from 1-2lbs per 11,500 gallons. If your pool is looking dull or cloudy you can use the dosage of 2lbs per 11,500 gallons.

HTH Super Shock n Swim

HTH super shock n swim pool shockHTH Super Shock is 15% stronger than regular HTH shock and swim. HTH super shock contains 53% available chlorine; it dissolves quickly for an immediate chlorine boost. This product not only kills tiny organisms but helps prevents future algae outbreaks. As always, it is best to dissolve the shock in a bucket of water before broadcasting it in to the pool. The dosage for HTH pool shock is 1lb per 12,000 gallons, it is completely safe to swim after shocking; no need to wait! HTH pool shock can be used on any pool surface; it has a fast dissolving formula so it will not stain plaster or bleach vinyl liners.


cloud out pool shocksCloud-out pool shock is used for biguanide pools, but also works in chlorinated pools. If you use Baquacil, Splashes or Soft Swim in your pool, Cloud Out is for you. It acts as a clarifier and oxidizer and stays active in the water for 7-10 days. The dosage for this shock is 2lbs per 12,000 gallons. 1 pound of cloud-out is the equivalent to 1 gallon of peroxide. The perfect alternative to liquid peroxide shocks. Burns clean, restores water clarity almost instantly. Great for cloudy pool water treatment.

With the widest variety of pool shocks available, InTheSwim is your source when you want to Super-Chlorinate!



Lauren Dylla
InTheSwim Staff Blogger


The Many Types of Pool Shock — 7 Comments

  1. I need help! We bought a 10×30 easy set up pool brand summer waves and we have no idea how to shock it. Our water is at a 8.0 ph level o chlorine. We bought the in the swim pool shock and it says use 1lb per 10000 gallons, our pool is only 1050 gallons but it is turning green! What should we do we have 3″ chlorine tablets on hand but no device yet to put them in so we wanted to shock the pool ans get it clean and keep up with it any information would be greatly appreciated!

    • Hi Kara, first thing is to lower the pH level to 7.2. Chlorine loses over half of its potency at 8.0, costing you money, and wasting chemicals. For your pool that would be 2.5 oz of muriatic acid, or 3 oz of dry acid (pH decreaser). Add it directly to the pool, and allow 15 minutes for it to disperse, then shock the pool with 1/2 bag of shock. Pour it into a bucket filled with water, and use something to stir, to dissolve the granules, then pour into the pool. For the remaining half bag, immediately fold it up tight and use a large clamp or 2 paper clips to keep the bag sealed, to lock out moisture, insects, dirt, etc. Half open bags of shock can be hazardous, so be careful with them to keep them closed tightly, and separated from other chemicals, in a dry and clean location. Normally, you may only use 1/4 bag (4 oz) of shock for your pool, but if it’s already green, use 1/2 bag. If really, really green, use the whole bag.

  2. My pool is clear, and all the tests show everything in balance EXCEPT chlorine. There is no chlorine in the pool. I’m using 3 inch tabs in two chlorinatiors and continue to shock it yet no chlorine. The guy at Leslie’s says shock it again. I keep doing that with no results. Amy thoughts?

    • Hi Lauren, sometimes there are unseen, invisible solids in the water that are consuming chlorine. Other options are that the cyanuric acid level is too high (over 100 ppm), or the chlorine is dissipating on the long car ride to Leslies. Shocking again, with a greater quantity is often the solution, to break whatever it is that is consuming chlorine. Often a double or triple shock is needed, meaning instead of the normal 1lb of shock per 10,000 gallons, try 3 lbs per 10,000 gals, or more if algae or colored water is present. I concur, more pool shock can often be the answer.

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