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Liquid Chlorine: What You Must Know

Liquid Chlorine: What You Must Know
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As a pool owner, you will have to get fairly comfortable with pool chemicals and their uses. The more you know about the chemicals and the way to keep your pool clean, the better chance you have of being about to use your swimming pool all season.

Chlorine is something swimming pools have to have at all times. Checking chlorine levels and maintaining them is one of the most important parts of pool maintenance. Chlorine comes in a few different types and forms. In this guide, we discuss liquid chlorine and everything you need to know to ensure this product cleans your pool properly.

What Is Liquid Chlorine and What Is It Used For?

Liquid chlorine is a form of chlorine where a very high level of chlorine gas is mixed with caustic soda to create a liquid product. The liquid chlorine is very highly concentrated because of the difference in the production of this product. Although some pool owners will use liquid chlorine at their homes, this pool sanitizer is used in commercial pools most of the time.

In a commercial pool, the liquid chlorination would come in large drums, and it would be administered to help keep chlorine levels stable in a large and high-use pool. Since it is a bit stronger, it can be smarter for a pool with higher bacteria levels.

Is Liquid Chlorine the Same As Shock?

Liquid chlorine and shock have the same active ingredients; however, there are a few differences between them that are worth understanding. The liquid chlorine is obviously sold in a liquid-only status, and it is an unstabilized product.

This means that the liquid chlorine does not come with cyanuric acid in it, and therefore it will quickly dissipate in the water and be eaten up by the sun. Liquid chlorine costs quite a bit less than shock as well.

Granular shock is stabilized, so it does have cyanuric acid in it, and it usually comes in a solid form. The form will slowly dissipate. Sometimes the shock is sold in granules, and rarely can it be found in a tablet. Overall, both products have the end goal of helping pool owners keep their water cleaner; however, they work in slightly different ways.

Can You Buy Liquid Chlorine?

There are lots of options on the market for liquid chlorine. Prices will vary depending on the brand you choose and the size of the product you purchase. For the strength of the liquid chlorine, you may not need as much as you normally would with chlorine tablets. Most commercial pool owners will use a pool supplies company to have larger containers of chlorine delivered to their location.

When to Use Liquid Chlorine?

Liquid chlorine is mostly used in pools that have a high level of swimmers. This type of chlorine will get your pool chlorine levels back to where they need to be faster than other types of granular chlorine. Even though this chemical may seem like the best choice, there are a few things about it that could cause you to think twice about using it.

The first problem is that liquid chlorine has a high pH of 13. When you add products with a high pH to your pool, you will need to add cyanuric acid to your pool to help lower the pH and bring it into range. The cyanuric acid works as a stabilizer to ensure that the products you just put in the pool will stay in place and truly clean it.

Another issue with liquid chlorine can be pits potency. With the choices you have on the market, the liquid chlorine will be one of the strongest, and therefore it can be a bit damaging. If you have a vinyl liner pool, you may notice that the continued application of liquid chlorine is starting to stain or fade the pool walls.

In addition, liquid chlorine has been known to erode and break down pool walls. Typically if you follow the proper procedures when putting the liquid chlorine in the pool, you shouldn’t have these issues. It’s just important to know the downsides of the liquid chlorine before making this the choice for your pool.

Stabilized vs. Unstabilized Chlorine

Stabilized chlorine is that which comes with cyanuric acid as part of its ingredients. Cyanuric acid is also known as a stabilizer, and it will help to keep the chlorine from losing its effectiveness so quickly. When you use unstabilized chlorine, it will have a much shorter time in the pool before it starts to lose its effectiveness.

Many people then wonder why it would make any sense to use unstabilized chlorine. The reason behind this is that you are using too much stabilized chlorine; your pool could reach a point of chlorine lock. This is when the choline you are putting in your pool is no longer working to keep the pool clean.

In addition, some pools, like indoor pools or those in the shade most of the time, will have some issues with the sun not burning off enough chlorine. So essentially, if you use stabilized chlorine in these pools, your levels could remain too high at all times. You can avoid this issue by using unstabilized chlorine in the indoor or shade-covered variety of pools.


  • Both products are used to increase chlorine levels in the pool
  • Stabilized and unstabilized chlorine can come in granules or chlorine tablets
  • Both products will help to keep bacteria in the water at a much lower level


  • Stabilized chlorine tends to be higher in price
  • Stabilized chlorine contains cyanuric acid to keep chlorine stabilized

Liquid Chlorine vs. Granular Shock

Liquid chlorine and granular shock are both unstabilized. As we know from above, the unstabilized chlorine means that cyanuric acid levels in the chlorine or shock are not high. Essentially the products do not have any stabilizer in them.

Both liquid chlorine and granular shock are known in the pool industry for having higher levels of available chlorine. Essentially you will need to chlorinate your pool daily, and then you will need to shock it from time to time. When you shock the pool, you must use a sanitizing product that raises the chlorine level quite high and then lowers it back down.

Granular shock and liquid chlorine are known to kill all living microorganisms and bacteria in the pool. Essentially there is nothing that is going to escape what these chemicals can do. Therefore clearing cloudy pool water is much easier with liquid chlorine and granular shock. If you have an algae problem, this is one great way to fix it.

However, liquid chlorine and granular shock are not the same product. The liquid chlorine tends to be quite a bit less expensive than granules. In addition, it is heavy to carry around and has a shorter shelf life. Although liquid chlorine tends to be one of the most popular options, some will like how easy the granules are to work with.


  • High levels of chlorine available
  • Both can be used to kill off bacteria and algae in the pool
  • If you have a cloudy pool, these two options are more effective than your chlorine used for daily maintenance


  • Sold in different forms
  • Liquid chlorine is heavy and can be a bit more dangerous to work with
  • Chlorinating shock granules can be stored for a longer period of time
  • Sometimes shipping is not possible to consumers on large orders of liquid chlorine

Liquid Chlorine vs. Powder Chlorine

Liquid chlorine typically comes in one type, and it is unstabilized chlorine used in your pool. Powder chlorine or chlorine tablets are a bit different, and you will have more choices to make when it comes to putting the correct one in your pool. Many pool owners prefer powder chlorine because of the convenience. It is easier to store and easier to put in the pool than liquid chlorine.

When you choose powder chlorine, you will have to choose between lithium hypochlorite, di-chlor, and calcium hypochlorite. Each of these types of powder chlorine has a different level of both chlorine in and pH in their product. If you are experiencing issues with pH in the pool, you must take a look at the type of chlorine granules or tablets you are using.

One of the major reasons why pool owners will use liquid chlorine is that the costs associated with it are quite a bit lower. This same concept applies to the spa industry as well. However, the costs can be slightly lower because liquid chlorine is not a stabilized product. You can purchase powder chlorine in a stabilized chemical form, and therefore it lasts longer as well. People have to make a choice that works for their budget and their pool type as well.

For a large commercial-type pool, liquid chlorine will likely be the right choice. However, most residential pool owners will find that the granules or chlorine tablets are a smarter decision.


  • Both products will work to keep bacteria levels low
  • Liquid chlorine and powder chlorine have equal effects on skin and on sanitizing
  • Both products could have an impact on the pH level


  • The liquid chlorine is heavy and difficult to put into the water properly
  • Powder chlorine is typically stabilized
  • Powder chlorine is more money
  • Powder chlorine comes in several different types (Cal Hypo, Dichlor)
  • Chlorine granules tend to make it easier for a consumer to store the product, purchase it, and put it in the swimming pool

How to Use Liquid Chlorine In Your Pool

Using liquid chlorine in your pool will take a few more steps than using chlorine granules or chlorine tablets. Here are a few things to consider when using liquid chlorine in your pool.

Time of Day

It’s important to make sure that you are using liquid chlorine at night. Since chlorine is an unstabilized product, if you use it during the middle of the day, the sun will burn off its effectiveness before it doing its job in the pool.

We recommend using the liquid chlorine only at night so that it has some time to work prior to the sun coming up.


Liquid chlorine can be a dangerous product to work with. When working with liquid chlorine, you must be concerned both with inhaling the product and with the splash that can happen when you put the liquid chlorine in your pool water.

Always wear the proper personal safety equipment and ensure that you follow the guidelines recommended by the manufacturer. Most will have you pour the liquid chlorine directly into the pool water. Depending on how you are pouring, there could be splash that you will have to worry about when you use the product.

Always store liquid chlorine in a secure location where pets or children cannot reach it. This product does wonders to clean our pools, yet it is not the best choice when it comes to safety.

Checking and Testing Water

Before putting liquid chlorine in your pool, you must test the water. Since the liquid chlorine is so potent, you could easily make the mistake of adding too much liquid chlorine to your pool. Test the water prior to putting the chlorine in, and then recheck the water before swimming. If you don’t do this, you may struggle with a pool that has a difficult-to-control chlorine level.

In addition, you will want to pay attention to the pH level when using any products in your pool.

How Much Liquid Chlorine Should You Add?

When adding liquid chlorine to your pool, be careful as to how much you add. Some brands of liquid chlorine are more potent than others. Many pool owners don’t realize that the chlorine they put in the pool can differ from one manufacturer to another. This is why it’s important to find a brand that works and then stick with it.

The amount of liquid chlorine you add to your pool must be based on the size of your pool. Most products are sold so that you know exactly how much chlorine to put in for every 10,000 gallons. If you have a large pool, you are likely going to need to think about the kind of chlorine you use and which makes the most sense financially. To know the exact amount of chlorine to use, you must look at the product you are putting in the pool and the size of your pool.

Chlorinating Liquid Recap

Pool owners sometimes have to search for products that do a good job of taking care of their pools. You may think it is as simple as choosing chlorine from a shelf, but there is quite a bit more to it than that. When you are using chlorinating liquid or liquid chlorine, you will have to pay attention to other chemical levels in your pool.

Anything added to the pool could have a potential impact on the other levels in your water. There are lots of options out there between granules, chlorinating tablets, and powder chlorine. Do your research and find the product that makes the most sense for your individual pool.