This is the first part of a 2-part article series about swimming pool chemicals. This article will introduce what pool chemicals are and discuss the two most important ones – the sanitizers and the balancers.

Have you ever wondered what pool chemicals are for? Experts say it’s for cleaning. Don’t we use water to clean ourselves and everything else around us? Why is there a need to clean water?

Allow us to explain.

If you have a swimming pool, you cannot just fill it up with water and be done with it. Since the water in the pool is stagnant, it can grow algae. The Sun will also play a part in its growth. And once people start to swim in the pool, their skin cells, hair, and chemicals (from soap, shampoo, pool toys, and equipment) can get in the water. You can also add the dirt, debris and other natural contaminants from the environment.

Thanks to all of these, you will be left with a bacteria-infested pool that is dirty and unsafe for swimming. It can cause eye and skin irritation. And since water usually comes into your mouth while you swim, it is possible for you to develop stomach and other digestive ailments.

You need to do something about this. And that means learning everything you can about pool chemicals.

2 main pool chemicals

There are only a couple of areas that you need to remember about pool chemicals. You have the Sanitizers and Balancers to start with. There are also other Pool chemicals that you might need along the way. You also need to learn about these and how to shock your pool. These will be discussed in the second part of this article series.

So what are the sanitizers and balancers?

The sanitizers will clean the water and kill the bacteria in the pool. To make the sanitizers work, you need to balance the other attributes of the water. To be specific, balancers work on the pH, alkalinity, and calcium hardness in the water.


When someone swims in your pool, they will leave dead skin, hair, body oils, shampoo, soap, and lotion in there. You also have natural contaminants from bugs, birds, etc. You need to keep these contaminants from turning your pool into a bacteria-infested place.

This is where sanitizers come into play. Basically, sanitizers will combine all the unwanted contaminants, viruses, algae, and bacteria to neutralize them.

There are two types of sanitizers.


Chlorine is the most popular. It’s very efficient and affordable. For it to work, the chlorine should be 3ppm (parts per million).

This chemical works by oxidizing the contaminants. That means it goes inside the molecules to destroy them from the inside out. This leaves a waste product called Chloramines. This is what makes the pool smell and causes your skin to dry and your eyes to become irritated. You need to manage this by adding more chlorine, or in extreme cases, shocking it. This is okay since the oxidation process, although it removes the contaminants, will also make the chlorine ineffective. So you really need to add more chlorine from time to time.

Chlorine comes in two forms: granules and tablets. Granules need to be placed daily while the tablets are placed only once in a chlorine dispenser or automatic chlorinator.

If you have an outdoor swimming pool, it is best to use a stabilized chlorine. It has Cyanuric Acid that keeps the Sun from burning off the chlorine easily. But if your pool is not under the direct heat of the Sun, then unstabilized chlorine will work just fine.


Bromine is the other sanitizer that you can use. It ionizes the contaminants. It breaks the chemical bonds of the molecules to break them apart. The great thing about this is that it remains active longer than chlorine. However, when it breaks down, it leaves waste products known as Bromamines. This reduces the effectiveness of the bromine. To manage the bromamines, you also need to shock the pool.

Take note that the bromine that you buy will probably be mixed with chlorine to give its sanitizing qualities a boost. After putting the bromine, make sure the level is 5ppm (never lower than 3ppm).

Other sanitizers and pool chemicals

Apart from Chlorine and Bromine, there are other pool chemicals that can also be used as sanitizers.

Biguanide is a chlorine-free sanitizer that is also known as PHMB (Preservative-free polyhexamethylene biguanide). It is a medical chemical used as a surgical disinfectant. When put in the water, it forces the contaminants to bind into water-insoluble clumps. This will allow the filter to grab it. That means you may have to change or clean the filter more frequently. This does not have harmful waste products and is gentler for the skin, eyes, and even hair. However, it is more expensive, does not last as long, and is not as effective. It can also turn your pool water a bit cloudy.

Minerals can also be a great alternative. If you have a pool mineral system you can rely on metals like silver and copper to sanitize the water. Silver is a bactericide and copper can be an effective algaecide. These metals release positively charged ions when they get into contact with water. Any negatively charged contaminant will surely be destroyed. The mineral sanitizer systems usually include active ingredients like borates and magnesium chloride. These have added benefits to the skin. However, these may not be as effective in sanitizing the pool. It usually works best when combined with chlorine.


Now that you know more about the sanitizer pool chemicals, let us talk more about the balancers. As mentioned, there are water attributes that you need to balance for the sanitizers to work efficiently. There are three attributes that you need to work on: pH, Alkalinity, and Calcium Hardness.


pH measures a substance to determine if it is basic or acidic. The scale is between 0 and 14. The neutral state is 7. If the scale tips below 7, the substance is acidic. If the scare is above 7, the substance is basic.

Human bodily fluids have different pH levels. The oil in our skin, music, tears, etc. These can affect the pH level of the water. If it ends up being too high, that can have an effect on the water. The same is true for the rain, leaves, and other contaminants that land on the water. This is why you need to monitor the pH level of the water. It has to be balanced.

It is important to keep two pool chemicals available. One is the pH increaser and the other is a pH decreaser. Make sure the pH level is between 7.4 and 7.6 to leave room for the chlorine to work.


Another attribute that you need to balance is the alkalinity of the water. The alkaline works as the buffer against the pH. It absorbs the changes in the water to keep the pH level from going up or down drastically.

There is only an alkaline increaser that will help you increase the pH and alkalinity level. This is usually why it is advised that this should be added before the pH chemical.

If there is a need to decrease the alkaline levels, there is no specific pool chemical for that. What you can use is a pH decreaser. This can also effectively decrease the alkalinity of the water, and of course, the pH level as well.

This relationship is the reason why you need to work on the alkalinity first. Only then should you adjust the pH levels accordingly.

Admittedly, it will take a couple of tries to get the correct level – since you have to make sure that both the alkaline and pH levels are correct. But in case the alkalinity is very high, you can reduce it by using muriatic acid. Make sure the alkalinity remains between 100 ppm to 150 ppm.

Calcium Hardness

This is a measurement of the hardness or softness of the pool water. Admittedly, calcium hardness depends on where you live and what water you use to fill up the pool. Like the water that comes from a spigot is usually high in calcium and other minerals.

When the calcium level is low, it can cause scaling and corrosion in the walls and equipment of the pool. To avoid this, you need to add a calcium hardener increaser.

But if the calcium is too high, it will make the pool water cloudy. To remedy this, you can shock the pool. It should also be noted that the high pH level can also cause high calcium hardness. So before you correct this, you need to correct the alkalinity, pH, and finally, the calcium hardness.

In the next part of the article series, you will learn more about the other pool chemicals that help maintain the water in your swimming pool. The second article will also discuss tips on how to shock and test the pool water.

If you need recommendation which pool chemicals would be best for your pool, contact us today.