Pool & Pond

Best Pool Shock – Buyer’s Guide and Reviews

If you’re a pool owner, you know that maintaining your pool’s cleanliness and clarity is crucial for a safe and enjoyable swimming experience. One of the most important steps in pool maintenance is using pool shock, a powerful oxidizing agent that helps eliminate bacteria, algae, and other contaminants in your pool water. But with so many pool shock options available on the market, how do you know which one to choose?

In this blog post, we’ll explore the best pool shock options and what to consider when selecting the right one for your pool. We’ll cover factors such as strength, type, and cost-effectiveness, as well as provide tips for using pool shock safely and effectively. So, whether you’re a seasoned pool owner or just starting out, read on to learn everything you need to know about the best pool shock for your pool.

1. Aqua Chem Shock Xtra Blue – Best Shock for Pool

Aqua Chem Shock Xtra Blue for Swimming Pools sells a five-pack of one pound bags for a very low price. This shock will kill both bacteria and algae in your pool’s water. Aqua Chem Shock Xtra Blue also helps to create sparkling water. It can be used in any pool type. The product reduces the odor of chlorine and lessens irritation caused to the eyes. Aqua Chem Shock will not increase the pH level of your pool water.

This shock allows you to get back in the pool faster than other options available. Aqua Chem Shock Xtra Blue quickly eliminates bacteria and algae and includes extra ingredients that help clear cloudy water.

You end up with sparkling water that is pH balanced and is ready to swim in as little as 15 minutes after you add it.

This is a cheap buy for five pounds of shock. If you are going to be needing this much over the course of a season, it is a good option. The extra chemicals that make your pool water sparkle and the ability to reduce the odor of chlorine and help lessen eye irritation are great benefits of this product as well.

Best Way to Shock a Pool

Pros
  • Kills bacteria and algae
  • Reduces the odor of chlorine and irritation in the eyes
  • Creates clean, sparkling water
  • Fits any pool types
Cons
  • Make sure you are buying new bags that are not expired or about to expire

2. In The Swim – Best Pool Shock Treatment

The In The Swim Pool Shock contains over two-thirds calcium hypochlorite, and 24 one pound bags are being sold together. The price is at only a few dollars a pound for this powerful and effective shock treatment. A single bag is used for every 10,000 gallons of water a week.

In The Swim Pool Shock provides a quick boost of chlorine when you need it. This is a great product to begin the swim year off with and to boost chlorine levels quickly. Make sure that you mix this product in a bucket of water to dissolve it before pouring it in the water.

This 24 pounds of strong pool shock should last you the whole year. Using only one bag a week per every 10,000 gallons of water, this is a strongly concentrated pool shock that will make all the difference in your pool.
Pros
  • 24 one pound bags for a cheap price
  • Powerful and effective pool shock
  • Over two-thirds Calcium Hypochlorite
Cons
  • Wait for two hours after use before swimming
  • Thick granules are hard to dissolve
  • Customer service is substandard

3. Doheny’s Super Shock – Best Cal-Hypo Pool Shock

Doheny’s Super Pool Shock contains the active ingredient calcium hypochlorite that helps clear out the most contaminated pools. This is also a deal that includes 24 one pound bags together at one great low price. It is very comparable to the In The Swim Pool Shock with roughly the same percentage of the active ingredient.

The shelf life of this product is said to be between two and three years which can make it a valuable purchase. If you are buying enough for a single year and you go over a bit, the product won’t be wasted. These one pound bags are enough for 10,000 gallons of water and can be used weekly.

This is another great pool shock product at a great price. It is cheap, effective, and can last up to three years.

Make sure that you dissolve this shock in a bucket of water before you put it in your pool to avoid any damage that the chlorine may cause.
Pros
  • Strong and concentrated pool shock
  • 24 one pound bags for a very cheap price
  • Quickly change the chlorine level to kill bacteria and algae
Cons
  • Granules don’t dissolve easily
  • Leaves a residue on the bottom of your pool and the surface of the water
  • Impurities clog pool’s filters

4. Clorox Pool & Spa Shock Xtra Blue Review: Best Pool Shock for Algae Killing

The Clorox Pool & Spa Xtra Blue is a powerful shock that has a few extras included. Instead of being in bags, this product comes in a bottle that is easy to pour. This makes using it far easier than having to rip open pound bags and try to pour them into a bucket.

This product contains crystals that kill blue algae. It also prevents and kills black, green, and mustard algae from getting in your pool. This 12 pounds of pool shock will also help make your pool’s water look clearer.

This is a powerful product in a much more convenient packaging. One pound of this shock is used for 12,000 gallons of water. You use less than the other products. It’s great for maintenance and is strong enough only to be used once a month instead of once a week.

How to use Clorox Pool and Spa Shock

Pros
  • Crystals kill blue algae
  • Prevents and kills black, green, and mustard algae
  • Sold in an easy to pour bottle instead of a bag
Cons
  • Leaves residue on your filter
  • Some packages seem to work better than others

5. In The Swim Chlorine-Free – Best Weekly Maintenance Pool Shock

The In The Swim Chlorine-Free Pool Shock has the active ingredient Potassium Mono persulfate that make up almost half of the product. This is a sale of 24 one pound bags at a very low price.

This chlorine-free shock eliminates the growth of algae and other harmful bacteria in your pool. It works great in a pool that is sanitized with bromine. This product burns away dead chlorine cells providing a higher free chlorine reading. This is a great shock to use for maintenance shocking of your pool.

This is a great non-chlorine option that improves the health of the water in your pool. These 24 one pound bags will work great in a pool that is sanitized with bromine. Its price is just slightly higher than the other options.

Pros
  • Non-chlorine alternative
  • Great for pools sanitized with bromine
  • Eliminates the growth of algae and other bacteria
  • You can swim immediately after treatment
Cons
  • If your chlorine level is low, this won’t help improve it

Best Pool Shock – Buyer’s Guide

With all the different options for shocking your pool, it is hard to know what direction to turn. Hopefully, the buyer’s guide that I provided helped to give you more knowledge about what you need in your pool. If the buyer’s guide was successful, you should have no problem picking out the product that will benefit you and your pool the most without damaging it.

Different Types of Pool Shock

Three different kinds of pool shock chemicals are available. They are calcium hypochlorite, sodium di-chlor, and potassium mono persulfate. There are two ways that you can buy them as well. You can buy these in a liquid form or a granular form, referred to as powdered shock.

1. Calcium Hypochlorite

This is the most popular type of shock that’s used and the strongest shock that is available. It dissolves quickly, and the sun’s UV rays burn it off without increasing the cyanuric acid level of the pool.

Although it dissolves quickly, you should dissolve it in another container before adding it to your pool. If you don’t, it can cause pin holes to form in your vinyl liner or bleach the pool’s surface.

If you buy Calcium Hypochlorite at a regular store, it will be weaker in comparison to the same thing bought from a swimming pool supplier. Other stores have restrictions on the type and potency of the chemicals that they carry.

This type of shock will raise the pH level of a swimming pool when added to it. You should add this type of shock in the evening and resume swimming when the chlorine level has returned to normal.

2. Sodium Di-Chlor

Sodium di-chlor dissolves more slowly and is a granular chlorine. It lasts longer in water than Calcium Hypochlorite does. This type of shock includes a stabilizer that increases the cyanuric acid level in the water of the swimming pool.

It can be used as either a shock treatment or a maintenance chlorine. Sodium Di-Chlor will raise the pH level when it is added to a swimming pool. This shock should be used in the evening, and you can resume swimming once the chlorine level has returned to normal (after 15-30 minutes).

3. Potassium Mono Persulfate

Potassium Mono persulfate is a shock that is based on oxygen which contains no chlorine. This type of shock is usually used to oxidize the water in your pool and remove any contaminants. It helps the chlorine work better.

Potassium Mono persulfate is often referred to as “shock and swim” since it can be added anytime during the day. You can resume swimming only 15 minutes after this had been added to your swimming pool. Non-chlorine shock does not affect the cyanuric acid that is in a pool.

Which is the Best Pool Shock to Use

The type of shock that you use depends on the chemistry of the water and the reason for doing the shocking:

  • If you have water that is green, you should use the Calcium Hypochlorite.
  • If you are doing weekly maintenance and the water looks clean, any of the three types will work.
  • You should use the non-chlorine shock every other week or before you have a lot of swimmers in the pool.
  • The non-chlorine shock should also be used if bromine is the primary sanitizer of your pool.

1. For Vinyl Pools

Vinyl, or polyvinyl chloride (PVC), is made by joining chlorine and ethylene. It is then made into rolls of a thin, flexible material that is used to line both in-ground and above ground pools.

Even though vinyl is made from chlorine, having your water over-chlorinated for too long of a period will draw resins from the vinyl. This will cause it to lose its plasticity. Vinyl liners getting bleached is another problem caused when powdered chlorine shock is added to a pool and sinks to the bottom before it has a chance to dissolve.

Non-chlorine shock is the best pool shock for vinyl liners. It is completely safe to use in a vinyl pool.
The best shock for above ground pools is chlorine shock. Use a pool shock that has 65% minimum available chlorine.

You can pour this directly into the pool and swim soon after that. It provides full sanitization in a fourth of the time chlorine takes. If you are using Calcium Hypochlorite, make sure that you completely dissolve it before adding it to the pool. The same thing goes for potassium mono persulfate. This will take longer to dissolve so be careful. If this isn’t done correctly, it will ruin the vinyl of your pool.

2. For Fiberglass Pools

A fiberglass pool uses a molded shell of fiberglass that is coated with a gel coat. It is less affected by chlorine because of its durable surface. To better care for the gel coat on the fiberglass shell, make sure that you dissolve your shock in a bucket that’s full of water before adding it to your pool. You can also use all three types of shock in this type of pool. The faster the shock dissolves, the better it is for your pool.

3. For Concrete Pools

A concrete shell that’s covered with a layer of waterproof plaster is used for concrete pools. Sometimes that plaster is mixed with quartz or other fillers to add strength, color, and texture to the shell. You can use just about any shock in a concrete pool. The plaster that doesn’t contain any fillers tend to develop etching and pitting from pool shock. This is especially valid for the first year.

You can use any of the three types of shock for a concrete pool.

When’s The Best Time to Shock My Pool?

If you shock your pool at the right time, it can make quite a difference to your pool. Shocking your swimming pool in the middle of the day during direct sunlight will cause your pool shock to burn out of the pool more quickly. The best time to add shock to your swimming pool is as the sun is going down after direct sunlight has passed over the pool.

How Much Shock Should I Buy?

You can save cash by purchasing pool shock in bulk, but make sure that you do not have too much left over. The shelf life of pool shock is only around one year, and if your shock goes past that date, the potency will slowly decline, leaving you with a swimming pool with weak chlorine levels. You should buy new pool shock every year.

To calculate how much shock you will need for an entire season, you will need to know a few things. First, you will need to know the size of your pool. The second thing to look at is the condition of the water in your pool. If it has been green ever since it closed or turns green often, you will need to use more shock. You will also need more shock if you use a safety mesh cover instead of a regular pool cover.

You will also need to think about how often you swim in the pool. The more often a pool is used, the more often you will need to add shock. People leave bacteria behind when they swim that the chlorine is used to kill off. The lower the chlorine level is in your pool, the more often you will need to shock it.

Many factors go into knowing how much shock to purchase for the pool season but make sure that you do not buy too much. This extra will lose its potency after a year and not work the way it is supposed to.

Should I Use Powdered Shock or Liquid Shock?

When using liquid pool shock, there is next to no chance that you will damage the pool or the liner. With powdered pool shock, there is a chance to do some damage if you’re not careful when adding it. A cement swimming pool will not be damaged by powdered shock, but there is a chance of leaving large quantities in different areas. You will have to use a swimming pool brush to try to move it around and dissolve it if that happens.

It is best to pre-mix shock to ensure that the powder gets broken up in the water and no deposits of shock are left anywhere on the pool floor. Liquid shock is a safer option while powdered shock will not cause any damage if added to a pool correctly.

Always read manual before using any type of the shock!

Can I Use Something Other Than Shock?

The most commonly used product for keeping a swimming pool free of bacteria is chlorine. There are many benefits of using chlorine in your pool, but it does negatively affect some people. There are other options if you are sensitive to chlorine. Such natural product as Pool Perfect + PHOSfree (that work using natural enzymes) will help to keep your pool water clean. They will keep your pool blue as well as free of bacteria. It is more expensive but is a great choice if your skin becomes irritated from chlorinated pool water.

Baquacil is another alternative to chlorine for keeping bacteria out of your pool. This product is a bit more expensive though.

You should never mix pool shock and Baquacil. If you choose to try Baquacil, you should use it for the rest of the season.

What Should I Look For in the Ingredients of Pool Shock?

You should always look at the label and see what a shock is made out of. You will want a product that contains a high percentage of active chlorine. That is the most important ingredient to look for. If you are buying pool shock online, there should be a page telling you exactly what the shock is made out of.

I think that is just about all the information I can give you about choosing the right pool shock. Hopefully, this guide helped clear up some questions you had.

View Comments

  • Thank you so much for all the time you spent giving all the info.. this is my first two months with my new house which has a pool. I have spent over $800 last sixty day with a store telling me I need 12 LB of this, 24 LB of that, PH up, Ph down, Alkaline is low, chlorine is up, need to vacume and waste... I have used the Clorox as per your review and had a blue clear water in 24 hrs. I only spent $49 for the 12 LB. thank you so much

  • Should this be added to the skimmer to travel out through the filter since it's granular? I have an above ground vinyl pool.

  • I always added my shock thru the skimmer, so I did with the clorox blue, never again. It clogged the fingers almost immediately, a blue residue on the entire filter. Now I need to figure out how to clean them.

  • You speak about Di-Chlor Shocks but do not mention anything about Tri-Chlor Shocks. What is the difference between the shocks (pros & cons) and which is most effective for an inground concrete pool ?

    • Hi Michael!
      What shock will work best is a matter of opinion. Below are some bullet points:

      1. Both are stabilized forms of chlorine
      2. Dichlor is typically a fast dissolving chlorine
      3. Trichlor is typically slow dissolving chlorine

      Trichlor and Dichlor shocks are compatible with concrete pools.

  • Great info thanks and so I’m clear on
    New in ground vinyl liner care , it is best to use non chlorine shock?
    What is recommended?
    And for regular maintenance?
    i have used a chlorinator with 4or 5 3 inch tabs that last 6-7 days.
    Should I change that or the chlorine tabs are ok for regular but non chlorine for shocking?
    Appreciate your recommendations.

    • Hello!

      While a vinyl liner is more susceptible to bleaching from granulated chlorine, chlorine-based shocks can still be used. For all chlorine shocks, when you broadcast them in the pool you’ll want to make sure any granules dissolve before reaching the bottom. If you do see some particles make it to the bottom, brushing a few times will dissolve the remaining granules. In addition, you’ll want to shock at least once a week to prevent a buildup of material in the water that can lead to haziness or combined chlorine.

      Make sure prior to shocking that your pH and Total Alkalinity are both in range.  Adding shock when the pH is low can cause damage to the liner.  For an inground pool with a vinyl liner, also make sure your Calcium Hardness level is at 200 or higher.  If the level is below 200, it can cause the water to try and pull calcium from other sources and also potentially damage the liner.  Having your water chemistry in range and making sure you brush any undissolved product off the liner are key with a vinyl liner. 

      Non-chlorine shocks can also be used and do not bleach liners. However, they don’t eliminate bacteria and algae and work best to oxidize non-living material like greases, oils, and bather waste.

      The type of shock to use really depends on what the pool is experiencing. If you’ve had a lot of rainfall and the water has a tint of green, then a chlorine shock will be necessary to eliminate the green. A pool that had a lot of usage from people could benefit from both chlorine or nonchlorine shock.

      Regardless of what shock method you use, you’ll still want to use tablets to maintain a chlorine residual in the pool.

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Published by
David Moore

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