What Chemicals Are Used To Keep Swimming Pools Clean?

Marjan Sokolovski

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Chemicals Are Used To Keep Swimming Pools Clean

What Chemicals Are Used To Keep Swimming Pools Clean

When it comes to enjoying a refreshing dip in the pool, the crystal-clear water we all love doesn’t just happen by chance. 

Behind those glistening waters lies a meticulous science, and at the heart of it are various chemicals that play a crucial role in maintaining pool hygiene and water quality. 

In this blog post, we’ll dive into the world of pool chemistry and answer some of the most frequently asked questions about the chemicals used to keep swimming pools clean and safe for swimmers. So, stay focused till the end. 

What Chemicals Are Used To Keep Swimming Pools Clean?

Swimming pools are kept clean using a combination of chemicals to maintain water quality and prevent the growth of algae and bacteria. Some essential pool chemicals include:


The most common sanitizer used to kill bacteria and pathogens in the pool water.

pH Adjusters

Chemicals like pH increaser (sodium carbonate) and pH reducer (sodium bisulfate) are used to regulate the water’s acidity or alkalinity.


These chemicals prevent and control the growth of algae in the pool.

Calcium Hardness Increaser

Used to maintain the proper calcium levels in the water to prevent damage to pool equipment and surfaces.

Stabilizer (Cyanuric Acid)

Helps maintain the effectiveness of chlorine by preventing its degradation from sunlight.

Shock Treatment (Calcium Hypochlorite or Sodium Dichlor)

A strong dose of chlorine is used to eliminate contaminants and restore water clarity.


Aid in removing particles and cloudiness from pool water.

Metal Sequestrants

Prevent metals like iron and copper from staining pool surfaces.

Sodium Bicarbonate

Used to adjust the pool’s total alkalinity.

These chemicals, when used in appropriate quantities and monitored regularly, help keep swimming pools clean and safe for swimmers.

Use of Chlorine Compounds to Clean Swimming Pool

Use of Chlorine Compounds to Clean Swimming Pool

Chlorine compounds are widely used to clean and sanitize swimming pools, effectively killing bacteria, viruses, and other contaminants. Here’s a brief overview of their use, along with their pros and cons:

How to Use Chlorine Compounds

Chlorine Tablets or Granules

These are added directly to the pool water or through a chlorinator device. The dosage depends on the pool’s size and current chlorine levels.

Liquid Chlorine

Often poured directly into the pool or added via a chemical feeder. It’s essential to follow manufacturer instructions for dosing.


Effective Disinfection

Chlorine is highly effective at killing harmful microorganisms, making the pool safe for swimmers.


Chlorine is relatively affordable compared to other sanitizing methods.


Chlorine can be used in various pool types (e.g., in-ground, above-ground) and sizes.

Easy Maintenance

With regular testing and adjustments, maintaining chlorine levels is straightforward.


Irritating to Skin and Eyes

Chlorine can cause skin and eye irritation, especially if levels are not properly balanced.

Chlorine Odor

The distinct chlorine smell can be unpleasant for some swimmers.

Potential for Chloramines

Chloramines formed when chlorine reacts with contaminants, can lead to a chlorine “smell” and may require additional shock treatments.

Handling Hazards

Chlorine compounds can be hazardous if mishandled or mixed with incompatible chemicals.

Environmental Impact

Chlorine byproducts can harm the environment if not managed correctly.

Chlorine compounds are a highly effective and cost-efficient method for pool sanitation. 

However, proper handling, monitoring, and maintenance are crucial to mitigate potential drawbacks like skin irritation and the formation of chloramines.

What Are the pH Balancers Chemicals Used in Swimming Pools?

Swimming pools require pH balancers to maintain the water’s acidity or alkalinity within a proper range. Common pH balancer chemicals used in swimming pools include:

Sodium Carbonate (Soda Ash)

This chemical is used to raise the pool’s pH levels when the water is too acidic.

Sodium Bisulfate (Dry Acid)

It is used to lower the pH levels when the water becomes too alkaline.

Muriatic Acid

Another option for reducing pH levels, muriatic acid is a strong acid that must be handled with care.

Sodium Bicarbonate

Also known as baking soda, it is used to increase total alkalinity and stabilize pH levels.

These chemicals help maintain the pool’s pH within the recommended range (typically 7.2 to 7.8) to ensure water quality, prevent equipment corrosion, and enhance swimmer comfort.

Use of Algaecides in Cleaning Swimming Pool

Use of Algaecides in Cleaning Swimming Pools:

Types of Algaecides

There are several types of algaecides available for pool maintenance, including:

Copper-Based Algaecides

These algaecides contain copper compounds and are effective against a wide range of algae types. They are often used for preventative measures.

Quaternary Ammonium Algaecides

These algaecides disrupt the cell walls of algae, preventing their growth and reproduction. They are often used to treat existing algae problems.

How to Use Algaecides

Using algaecides in your swimming pool typically involves the following steps:

Test Water

First, test the pool water to determine the type and severity of the algae problem.

Calculate Dosage

Follow the manufacturer’s instructions to calculate the appropriate amount of algaecide needed based on your pool’s size and the algae issue.


In some cases, you may need to pre-dilute the algaecide with water before adding it to the pool.


Pour the algaecide directly into the pool, spreading it evenly across the water surface. Avoid pouring it near pool skimmers or drains.


Run the pool’s circulation system for several hours to distribute the algaecide evenly.


Re-test the water after a day or two to ensure the algae problem has been resolved. If needed, repeat the treatment.

Pros of Using Algaecides

Algae Prevention

Algaecides are effective in preventing algae growth, which can help maintain water clarity and aesthetics.


They can be used to treat existing algae blooms and restore water quality.


Algaecides are typically compatible with other pool chemicals.

Cons of Using Algaecides

Temporary Solution

Algaecides provide temporary relief from algae problems and may require regular maintenance doses.


Regular use of algaecides can add to the overall cost of pool maintenance.

Chemical Residue

Overuse of algaecides can lead to a buildup of chemicals in the water, potentially causing imbalances or other issues.

Environmental Concerns

Some algaecides may have environmental impacts, so it’s essential to choose products carefully and follow recommended dosages.

Algaecides are valuable tools in maintaining a clean and clear swimming pool. They are effective in both preventing and treating algae issues.

Is Clarifier Essential to Clean a Swimming Pool?

A clarifier is not essential for routine swimming pool maintenance, but it can be a useful tool to improve water clarity under certain circumstances. Whether or not you need a clarifier depends on the specific condition of your pool water and your aesthetic preferences. Here’s some information to consider:

When Clarifiers Can Be Beneficial?

Cloudy Water

If your pool water appears cloudy due to fine particles suspended in the water, a clarifier can help gather these particles together, making it easier for the pool’s filter system to remove them. This can result in clearer water.

Enhanced Aesthetics

Some pool owners use clarifiers to achieve exceptionally clear and sparkling water, which can be desirable for special occasions or if you have high aesthetic standards.

Reduced Filter Clogging

Clarifiers can reduce the strain on your pool’s filtration system by aggregating particles, potentially extending the life of your filter elements.

When Clarifiers May Not Be Necessary?

Proper Maintenance

If you maintain your pool regularly with proper filtration and chemical balance, you may not encounter significant water clarity issues that necessitate a clarifier.

Excessive Use

Overuse of clarifiers can result in over-treating the pool, leading to water imbalances or the need for additional chemicals to correct the situation.

Environmental Considerations

Some clarifiers contain chemicals that may not align with your environmental goals, so their use should be considered carefully.

While clarifiers are not essential for routine pool maintenance, they can be beneficial in specific situations where water clarity is a concern. If your pool water is consistently clear, you may not need to use clarifiers regularly.

Benefits of Using Stabilizers and Shock Treatment

Check out the following section to learn about the benefits of using stabilizers and shock treatment in swimming pools. 

Benefits of Using Stabilizers (Cyanuric Acid) in Swimming Pools

Chlorine Protection

Stabilizers help protect chlorine from the degrading effects of sunlight, which can extend the lifespan of chlorine in the pool water.

Cost Savings

By reducing the rate at which chlorine dissipates, stabilizers can lead to cost savings since you won’t need to add chlorine as frequently.

Consistent Chlorine Levels

Stabilizers help maintain more consistent and effective chlorine levels, ensuring proper sanitation and water clarity.

Benefits of Using Shock Treatment in Swimming Pools

Rapid Sanitation

Shock treatment is a powerful way to quickly raise chlorine levels in the pool, making it effective at killing bacteria, algae, and other contaminants.

Algae Control

Shock treatments can effectively control and eliminate algae blooms, restoring water clarity and preventing further algae growth.

Removal of Chloramines

Shocking the pool helps break down chloramines, which are responsible for the “chlorine smell” and can irritate swimmers’ eyes and skin.

Water Clarity

Shock treatments can improve water clarity by eliminating organic matter and particulates that can cause cloudiness.

Routine Maintenance

Regularly shocking the pool can help prevent the buildup of contaminants and ensure consistent water quality.

It’s important to use stabilizers and shock treatments appropriately and in accordance with manufacturer instructions. Overusing or misusing these chemicals can lead to water imbalances, reduced effectiveness, or other issues.

Swimming Pool Cleaning Tips

Here are some swimming pool cleaning tips to help you maintain a clean and inviting pool:

Skim and Remove Debris Daily

Use a skimmer net to remove leaves, insects, and other debris from the pool’s surface. This prevents the debris from sinking and becoming harder to clean.

Clean Skimmer Baskets and Pump Baskets

Regularly empty and clean the skimmer and pump baskets to ensure proper water flow and filtration.

Brush the Walls and Floor

Use a pool brush to scrub the walls and floor of the pool to dislodge algae and dirt. Brushing should be done weekly or as needed.

Vacuum the Pool

Use a pool vacuum to clean the bottom of the pool and remove settled debris. You can choose from manual, automatic, or robotic pool vacuums.

Check and Maintain Water Chemistry

Regularly test and adjust the pool’s pH, chlorine levels, alkalinity, and calcium hardness to ensure water balance. Imbalanced water can lead to water quality issues.

Shock the Pool

Periodically shock the pool to raise chlorine levels and kill bacteria, algae, and other contaminants. Follow the manufacturer’s guidelines for dosage and frequency.

Clean the Filter

Depending on the type of filter (sand, cartridge, or DE), clean or backwash it as needed to maintain proper filtration.

Check and Maintain Pool Equipment

Inspect pool pumps, filters, heaters, and other equipment regularly to ensure they are functioning correctly. Replace or repair any damaged or malfunctioning parts promptly.

Maintain the Water Level

Keep the water level in the pool within the recommended range. Add water when it’s too low or use a hose to drain excess water if it’s too high.

Use Pool Covers

Covering your pool when it’s not in use can help prevent debris, evaporation, and heat loss. There are various types of covers, including solar covers, safety covers, and winter covers.

Trim Landscaping

Trim trees and shrubs around the pool area to minimize the amount of leaves and debris falling into the pool.

Regularly Clean Pool Accessories

Clean pool toys, floats, and other accessories to prevent them from introducing contaminants into the pool.

Schedule Professional Maintenance

Consider scheduling routine professional pool maintenance to address more complex issues and ensure your pool stays in top condition.

Winterize Your Pool (if applicable)

If you have a seasonal pool, follow proper winterization procedures to protect it during the off-season.

Remember that pool maintenance is an ongoing task, and regular attention to these cleaning tips will help ensure your pool remains clean, safe, and enjoyable for swimming throughout the season.


What chemicals are commonly used to keep swimming pools clean?

Chlorine and bromine are the most common chemicals used for pool sanitation. Chlorine is widely preferred due to its effectiveness in killing bacteria and algae. Some pools also use saltwater systems, which generate chlorine from salt.

How does chlorine keep swimming pools clean?

Chlorine disinfects pool water by releasing hypochlorous acid, which eliminates bacteria, viruses, and algae. It also oxidizes contaminants and debris. Maintaining the right chlorine levels ensures safe and clean pool water.

Are there alternative chemicals for pool sanitation?

Yes, alternative options include bromine, ozone generators, and UV-C sterilizers. Bromine is similar to chlorine but less affected by pH fluctuations. Ozone and UV-C systems use ultraviolet light or ozone gas to sanitize pool water without adding chemicals.

What is the ideal chlorine level for a clean swimming pool?

The ideal chlorine level for a swimming pool usually falls within the range of 1.0 to 3.0 parts per million (ppm). This concentration effectively sanitizes the water while minimizing irritation to swimmers’ skin and eyes.

How often should pool chemicals be tested and adjusted?

Pool chemical levels should be tested at least once a week, with daily testing during periods of heavy pool use or hot weather. Adjustments can then be made as needed to maintain the proper chlorine levels and ensure a clean, safe swimming environment.

Wrapping Up

Maintaining a clean and safe swimming pool involves a careful balance of chemistry, and understanding the role of the chemicals used is essential for every pool owner. 

In this blog post, we’ve addressed some of the most common questions about pool chemicals, shedding light on their significance and how they contribute to the enjoyment of your pool. 

By arming yourself with knowledge, you’ll be better equipped to keep your pool water pristine, allowing you to dive into a season of aquatic fun with confidence and peace of mind. Best of luck. 

Photo of author

Marjan Sokolovski

I am a professional swimming coach who has been coaching for over 20 years. I have coached athletes in the Olympics and Paralympics, and I have also helped to train people across the world. I started my coaching career by teaching swimming lessons at a local pool. I was really passionate about teaching people how to swim, but I quickly realized that this wasn't enough for me. I wanted to make a difference in people's lives and help them achieve their goals. I started working with athletes in high school, college, and then professionally. The best part about coaching is that you get the opportunity to work with so many different types of people from all walks of life - it's just incredible! LinkedIn

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