Chlorination: 8 Best Types of Sanitizers for Your Pool

Since chlorination is used to kill bacteria and prevent biological contaminations, understanding which type of chlorine is best for your pool (residential or commercial) may be difficult. Worry not!  This article discusses the differences between chlorination products. And on how they work best for different types of pools. Additionally, it also discusses common questions most …


Since chlorination is used to kill bacteria and prevent biological contaminations, understanding which type of chlorine is best for your pool (residential or commercial) may be difficult.

Worry not! 

This article discusses the differences between chlorination products. And on how they work best for different types of pools. Additionally, it also discusses common questions most pool owners ask when choosing the best chlorine for their swimming pool.

Let’s get started.

What’s the Right Chlorine for Your Pool? Liquid Chlorine or Chlorine Tablets?

Liquid chlorine is the right choice for most residential pools. Because it is easy to adjust and scale. 

But, if your pool is a saltwater pool, liquid chlorine may not be ideal. The reason behind this is that it cannot stop algae from growing in saltwater pools.

In these cases, you would use tablets.

When Should I Use Liquid Chlorine for a Pool?

liquid chlorine for swimming pool

You can choose either tablet or liquid chlorine, depending on your needs. For instance, if you have an above-ground pool with no filtration system, using tablets will save time and money by cutting down the need for chemicals added to the swimming pool every month.

However, if you want to keep your swimming pool clean all year round, you will probably prefer to use liquid chlorine. It works better at killing algae than tablets do. You can even add more liquid chlorine during the summer months to help control algae growth.

How Does Liquid Chlorine Work?

The main difference between liquid chlorine and tablets is their method of action. Tablets contain active ingredients such as sodium hypochlorite, whereas liquid chlorine contains only chloride ions.

Liquid chlorine works by breaking down the cell walls of microorganisms such as bacteria and algae before oxidizing them, which kills or deactivates the organisms.

How Much Chlorine Is Enough?

The amount of chlorine needed varies based on several factors, but generally speaking, 1 ppm of free available chlorine suffices to maintain good swimming conditions.

To determine this number, multiply the number of gallons in the pool by 0.00013. Here is an example: If your swimming pool contains 4,978 gallons of water, multiply 4,978 by 0.00013. It will give you the result of 0.65 ounces of needed chlorine.

When Should I Use Chlorine Tablets for a Pool?

Tablet Chlorinate on Poolside

Chlorine tablets are great for maintaining safe swimming conditions in both indoor and outdoor pools. They are convenient because you do not have to measure out any chemical solutions.

Instead, drop one or two tablets into each side of the filter basket and let the pool run until the water turns clear again. Once the water clears up, remove the tablets and replace them with fresh ones.

Why Do We Recommend Chlorine Tablets Instead of Liquid Chlorine?

Tablets provide consistent results throughout the entire season. Unlike liquid chlorine, tablets will not evaporate or dissolve away once they are placed inside the pool.

Also, since tablets come premeasured, you know exactly how many tablets you put in the pool. With liquid chlorine, you might accidentally pour too little or too much.

What Is Chlorine Gas for Pools?

It comes down to personal preference. Both options offer advantages and disadvantages. We suggest trying both before making a decision.

Other Types of Chlorine Sanitizers for Swimming Pool

There are, however, some other types of chlorine sanitizers for swimming pools. These include chlorine gas, sodium hypochlorite, sodium dichlor, potassium monopersulfate (PoolShock), lithium hypochlorite, calcium hypochlorite (referred to as “cal-hypo”), chlorine dioxide, and chloramines.

Let’s check their differences below.

What Is Chlorine Gas for Pools?

Gas Chlorine for Swimming Pools

Chlorine gas contains 100% chlorine and is the most potent type of chlorine product available. As a result, pool maintenance specialists and public pool owners may use it to increase free chlorine levels in pools much more effectively than they can with conventional chlorine acid liquid solutions.

Because of its efficiency in both time and expense, chlorine gas is widely employed by professionals. In addition, chlorine gas is a great disinfectant, and it is available at a reasonable cost.

However, the expensive budget of maintaining equipment, increasing insurance rates, training requirements, transportation needs, and high toxicity levels have all contributed to a substantial reduction in its usage over the last several decades.

As a result, gas chlorine has been outlawed in several areas due to concerns about its safety. If chlorine gas is not handled properly, it may be hazardous and even fatal to health.

What is Sodium Hypochlorite?

liquid chlorine in beaker

Treatment of swimming pools with sodium hypochlorite is one way to disinfect the water in the pool. The disinfectant acts by releasing chlorine gas from the mixture. Chlorine is a type of gas that kills bacteria, viruses, and protozoa, which can cause illnesses in humans and animals when they swim in contaminated pool water.

Sodium Hypochlorite can also be used as a household cleaner to release hypochlorous acid in contact with water, which reacts explicitly with organic material.

What is Calcium Hypochlorite?

Calcium Hypochlorite on Palm

Calcium hypochlorite is an important chlorine compound for the preservation and disinfection of swimming pools. The chemical is often used to sanitize the water in pools and spas. It also kills bacteria and other pathogens that may be present in the water.

The use of calcium hypochlorite in swimming pools helps kill bacteria that can cause skin, ear, respiratory, and intestinal infections. It also kills viruses such as polio, rotavirus, norovirus (gastroenteritis), hepatitis A virus (infectious diarrhea), adenovirus (respiratory infection), warts caused by papillomaviruses (skin lesion), etc.

The pool sanitizer removes harmful bacteria and helps to prevent the growth of algae. It is recommended that you use chlorine-free calcium hypochlorite when creating a solution in your swimming pool. You will need to mix one-half gallon of this solution with every 25,000 gallons of water in the pool.

What is Dichlor (Sodium Dichloro-S-Triazinetrione)?

powder dichlor poured in pool

Dichlor is probably the “best of all worlds” chlorine sanitizer. It is usually found in concentrations of 60-65 percent, which is similar to cal-hypo.

It is a powder sanitizer, which makes it simpler to distribute throughout the pool than chlorine pills. It is stable, which means it may be used as both a chlorine sanitizer and shock.

One disadvantage of dichlor is that, like trichlor, it causes an increase in cyanuric acid levels in the pool. If cyanuric acid levels in your water rise to dangerous levels and you are forced to replace part of your water, this may be an issue. Another disadvantage of dichlor is that it is often much more costly than cal-hypo.

What is Lithium Hypochlorite?

Lithium hypochlorite is another alternative to chlorinating pool water. This product contains lithium chloride instead of sodium or potassium salts.

In addition to killing germs, it also prevents them from reproducing. Like many other chemicals, it must be mixed into the pool before use. For best results, add 1/4 cup per 10,000 gallons of water.

This product works well at low temperatures because its solubility decreases as temperature increases. At higher temperatures, however, it becomes less effective. To avoid problems with high temperatures, some manufacturers recommend mixing it only once during the season.

Another advantage of lithium hypochlorite is that it does not produce any toxic gases upon decomposition. But, it is highly corrosive, so it cannot be stored near metals or plastics.

What is Potassium Monopersulfate (PoolShock)

PoolShock is a chemical that kills bacteria and also prevents algae. It may be used on its own or in combination with other chlorine-based sanitizers.

This product usually comes in small, white packets that are dissolved in water before being added to the pool.

PoolShock is often highly concentrated, so that it may be too intense for spas and hot tubs. One disadvantage of this sanitizer is that extensive exposure can irritate skin and eyes because it contains sodium hypochlorite.

What Should I Do to Chlorinate My Pool if I Do Not Have an in-Line Chlorinator?

floating dispenser in pool

If you do not have an in-line chlorine chlorinator, the easiest way to chlorinate your pool is by using an injection system. These systems are often inexpensive and are easy to install. You can also use a floating dispenser that will slowly release chlorine into the pool. 

Although a floater does not spread chlorine as efficiently as an in-line chlorinator, it is still a very effective method of chlorinating your swimming pool.

Take Note: Always avoid putting chlorine pills into the skimmer baskets. Some pool providers may put chlorine pills straight into the pool’s skimmer baskets to prevent the need for additional equipment.

However, placing chlorine pills in these skimmer baskets is not advisable. They may do severe damage. You might wonder why?

Well, chlorine tablets in the skimmer baskets produce a dangerously high chlorine concentration into the swimming pool, which is dangerous to the swimming pool equipment. In addition, high amounts of chlorine close to the pool pump, pool filter, and pool heater may cause harm to these pieces of pool equipment. The pool heater is particularly prone to heater leak, which produces copper into the pool and eventually damages your pool plaster.

Remember, this is only a brief overview of swimming pool sanitizers. Whatever kind of pool sanitizer you’ve chosen, it is essential that you follow the manufacturer’s recommendations and instructions. At the end of the day, you want to ensure that both you and your pool area are safe.

Take into consideration how filthy your pool may get when comparing pool sanitizer and shock. As a general rule of thumb, regular cleaning is the number one priority in keeping your swimming pool in tip-top condition. 

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