Pool Sanitizer vs. Shock: Are they different?

Every once in a while, we hit the pool with some form of cleaner. Either it be for cleaning stubborn algae or pool germs (Bacteria, viruses, and parasites), pool sanitizers and shock is always needed. 

However, between pool sanitizer Vs. shock, which one should get the most priority? 

Frankly speaking, it depends on the pool condition. For a pool manifested with green or black algae, go for an instant pool shock. On the other hand, pool sanitizers are well off for regular usage. Daily use of pool sanitizers like chlorine (NaOCl) prevents the growth of organic pollutants. 

Here we have collected a head-to-head comparison between these two water disinfectants. Let’s see who churns out the best for us.

Pool Sanitizer vs Shock

Pool Sanitizer Vs. Shock: Comparison Chart

In a hurry? Just go through this comparison chart below for an instant picking: 

PropertiesPool SanitizerPool Shock
IngredientsSodium Hypochlorite (NaOCl) and some forms of hypochlorous acidTrichlor, cal-hypo, or dichlor
Toxicity LowHigh
UsageRegularlyOnly if the water get too dirty
Application of other compoundsNot neededPool chlorine is needed to boost the cleaning process
Germ removalYesYes
Amount needed1.3 ounces per 10000 gallons1 pound per 10000 gallons 
Use in chlorinatorsYesNo
Vulnerability to sunlightDegrades in active sunDegrades with or without the active sun

Pool Sanitizer: What is it?

A simple dip in the pool can shed thousands of organic matter from your body. The organic pollutants add up, creating the perfect breeding ground for bacteria, viruses, and so on. Luckily, we can take care of that with a few ounces of pool sanitizer. Here are some features of pool sanitizers: 

Kills all germs

Having activated chlorine as the base, pool sanitizers can remove nearly all forms of organic pollutants. Whether you own a public pool or a personal one, pool sanitizers can be a lifesaver. The chlorine and acid of pool sanitizers react with all organic germs, giving you a healthy pool for longer. 

Cost effective and highly efficient 

Pool cleaners aren’t cheap, especially if you need to use something regularly. The money adds up every month, which can be a bit expensive for some. However, pool sanitizers cost about 5 dollars per pound, and you need about 1.3 ounces of it per 10000 gallons of water. So you need about 3 pounds of pool sanitizer per month. 

Non toxic

If you keep the level of pool sanitizer at 5 to 10 ppm, you should be just fine. Turns out, pool sanitizers will hardly burn or do damage to swimmers at this level. You can enjoy it for hours without needing to stress too much about the dangers of chlorine. 

Ideal for regular use

Once you leave a pool as it is, the amount of pool contaminant increases. But hey, using about one ounce of pool sanitizer per 10000 gallons of pool water will stop any pool contaminants from spreading. You can use a chlorinator to disperse the pool sanitizer regularly and with minimal effort. 


  • Easy to use
  • Long lasting usage
  • Cheap and reliable
  • Low in toxicity
  • Highly effective against germs


  • Can’t clean pool filled with algae

Pool Shock: What is it?

Suppose your pool is fully contaminated with green or black algae. For this, you will need a cleaner that is more potent than regular sanitizers. Pool shocks are the best candidate for that. After applying just 1lb of pool sanitizer per 10000 gallons of water, your pool will find new life. 

The best part is, you don’t have to shock the pool more than once. Here are some features worth mentioning: 

Activates free-floating chlorine

Even if you put a lot of chlorine in pools, chances are other materials will form chemical bonds with it, rendering the NaOCl neutral. Pool shocks have trichlor, cal-hypo, or dichlor, which can separate the chlorine molecule and activate free-floating chlorine. The process will continue until you visually see a crystal clear pool of water

Breaks down algae clusters

Algae can form if the pool is left without chlorine or sanitizers for more than 3-4 days. A greenish-black hue will form on the crystal pool water. Not pleasant is it? Well, don’t worry. There is nothing a few hours of shock treatment can’t fix. 

Just leave a few lbs of pool shock directly to the pool and wait for algae filled water to clear up. You may need to add a few ounces of chlorine every once in a while for maximum cleaning.

One time use

Let’s face it. Pool shock is only the heavy stuff. What will you do with pool shock if the water is crystal clear, right? This is why shocking is a one-time thing, and you need it only if the water is highly contaminated. 

Solid and liquid variation

Are you having a hard time mixing pool shock in a cup before throwing it in the water? Though you don’t need to make a pool shock paste before applying, the process sure speeds things up. Turns out, pool shocks come in both solid and liquid variations. So, you can just pour a cup of pool shock in the pool without needing to mix it randomly. 


  • Comes in both solid and liquid variations
  • Regular usage isn’t needed
  • Breaks down any form of organic matter
  • Activates chlorine molecules


  • Make the pool unusable for about 24 hours
  • Too potent

Pool Sanitizer Vs. Shock: Head to head 

For us, this is a draw. Generally, pool shock is used when the floating algae or organic material goes out of hand. Pool sanitizers are more of a regular prevention kinda thing. If you don’t add pool sanitizers daily, the water may turn cloudy, and you will need pool shock afterward. Let’s see a few more differences between them:

Pool cleaning potency

When cleaning a pool filled with contaminants, it’s hard to consider anything else over pool shock. Pool sanitizers are good and all, but when it comes to a heavily infected pool, shock works the best. Additionally, you can add a bit of pool sanitizer and boost the shocking process.

Preventing germ buildup

To get rid of any germ buildup, pool sanitizers get the upper hand. Due to the potent nature of pool shock, we can’t use it regularly. Then again, a few ounces of pool sanitizer will work perfectly to prevent all sorts of germ buildup. 

Toxicity level

Trichlor, cal-hypo, or dichlor are more toxic than any regular pool sanitizers. You can’t use the pool for at least 24 hours after shocking. On the other hand, pool sanitizers will hardly do anything to swimmers. Just make sure the ppm is less than 10, and you are good to go. 

Application time

It shouldn’t come at a surprise to you that shocking is a complete process. Add a bit of shock every time the effect fades away. Repeat the process until the pool is completely clear. This process can consume a lot of time, and you need to restrain for 24 hours before using the pool. 

However, sanitizing needs only a couple of hours to finish. You can also put some pool sanitizer in a chlorinator and let it disperse slowly.

Regular usage

You don’t really need to shock pool water daily. Just keep the chlorine/sanitizer level to 5-10 ppm and stop worrying. Regularly using pool sanitizer will decrease the chances of organic contaminants, giving you a picture-perfect pool every time. 


Can I use shock as a sanitizer?

You can’t use shock as a pool sanitizer. The reason is pool shocks are more vigorous than regular pool sanitizers. We use pool sanitizers regularly to prevent organic matter from contaminating the pool. However, pool shock is for one-time use, and you need to avoid using the pool for a minimum of 24 hours. On the other hand, you can jump into a pool even right after you are sanitizing it. 

Is pool sanitizer the same as pool chlorine?

For the most part, pool sanitizers do contain regular NaOCl or chlorine. Other than chlorine pool sanitizers can also contain hypochlorous acid, which is great for killing and preventing germs. Similar to pool shock, pool sanitizers also contain chlorine, but it’s not completely chlorine inbuilt. So, whenever you see pool sanitizer written on the pack, don’t confuse it with plain old chlorine. 

End Note

Pool sanitizers are great if you want to sanitize the pool water almost daily. However, if the pool water looks dirty and a layer of algae floats in it, pool shock is the only option. 

You can try using sanitizers, but the end result won’t be pretty. On the other hand, a few lbs of shock will be enough to take down almost any pollutants. 

This is all for today. Let’s hit the sack. Have a good day.

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