What Pool Chemicals Do I Need? The Complete Guide

By Blue Cube on Thursday, 25th May 2023 in Tips & Tricks.
Large Format Tiled Pool with Contrasting step stones | Blue Cube Pools

Pool chemicals are essential for keeping the water in your pool clean and safe to swim in. 

Maintaining the right balance of chemicals is essential in order to ensure that your pool remains free from bacteria, algae, and other contaminants. 

On top of this, unbalanced levels of pH, chlorine, or alkalinity can cause discolouration in the water or even skin and eye irritations for swimmers.

Fortunately, maintaining the right balance of pool chemicals can be relatively simple if you understand the basics of pool water chemistry, what chemicals you need, and when to add them for effective pool maintenance.

With this guide, we’ll cover all these topics so that you can make sure your pool is in optimal condition, all year round.

Understanding swimming pool water chemistry

Swimming pool water chemistry differs vastly from that of freshwater or water from hot tubs. With the addition of chlorine and other disinfectants, the water in your pool is much more acidic than regular tap water. As such, it’s important to understand that pool maintenance involves balancing both the pH (acidity) levels and sanitiser levels.

So, first things first, let’s look at the main components that make up your pool’s water chemistry.

1. Chlorine levels

Your total chlorine (TC) levels are the combined amount of free chlorine and combined chlorine present in your pool water.

Free chlorine levels are the amount of chlorine in your pool that’s available to sanitize and disinfect your water, while combined chlorine has already reacted with contaminants in the water and is no longer effective for sanitation.

It’s important to test your total chlorine level (also known as “chlorine demand”) as it helps to determine how much chlorine you need to add.

Free chlorine (FC) is one of the most important components when it comes to maintaining a healthy and safe swimming pool. FC comes from a chlorinated sanitiser, such as liquid chlorine or calcium hypochlorite, and is used to control bacteria, algae growth, and other contaminants in pool water.

While chlorine is a crucial pool chemical, it’s important to make sure you have the right amount of free chlorine in the water so that your swimmers are not exposed to any health risks. FC levels should generally remain between 1-3 ppm for optimal results.

2. pH levels

pH levels are important for keeping the water in your pool clean and safe. You need a balance of different chemicals to make sure the pH level is right, which helps stop bacteria and other things that could make you sick.

Your swimming pool pH is impacted by the concentration of hydrogen ions (pH is measured on a scale of 0-14, with 7 being neutral). An ideal pH level should be between 7.2 and 7.6. 

When your pool’s pH level is above that range, it can cause eye and skin irritations for swimmers. Lower levels can lead to corrosion and scaling on the pool’s surfaces. As such, it’s vital to regularly test your pH levels and treat as necessary.

3. Ammonia

Ammonia is a chemical that can be found in swimming pools if the levels of chlorine and pH are too low. But it’s not a chemical you want in your pool – it’s a result of body oils, sweat, and other contaminants that react with other chemicals in the water to form ammonia.

High levels of ammonia can cause eye and skin irritations for swimmers as well as discolouration of the pool walls and other pool surfaces. It’s, therefore, crucial to test for it on a regular basis. 

To test for ammonia, you need to use special testing tools like strips or kits or a pool water treatment service.

4. Total Alkalinity (TA)

Total alkalinity refers to the amount of alkaline substances in your pool water. Alkaline substances are elements or compounds that can raise the pH level of a solution. They act as a buffer against sudden changes in pH, which helps maintain a stable pool environment.

As such, it’s crucial to test alkalinity levels regularly. The ideal range for total alkalinity (TA) levels is between 80 and 120 ppm, as this helps keep pH levels within a stable range.

If your TA levels are too low, it can lead to rapid pH changes that can cause eye irritation or skin rashes among swimmers. If your total alkalinity is too high, your pH level will be almost impossible to change.

5. Calcium hardness levels

Calcium hardness (CH) levels play an important role in water chemistry, as calcium hardness affects calcium and magnesium levels, keeping them balanced. Having too much calcium in the water can cause scaling on pool surfaces, while too little can lead to corrosion and etching of the surface.

The ideal range for a pool’s calcium hardness level should be between 200-400 ppm, depending on your specific pool’s needs.

When testing for CH, you need to use a special kit or strips. Remember, it’s important to keep an eye on these levels as they can have an adverse effect on your pool if not managed correctly.

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Remember: Regular testing and maintenance of free chlorine, pH levels, ammonia, total alkalinity, and calcium hardness will help to keep your swimming pool clean and safe. Monitoring these key components of pool chemistry will ensure your swimmers always have a safe, enjoyable swimming experience.

What is a pool water treatment?

A professional pool water treatment is the best way to ensure your balanced pool water that is squeaky clean and safe for swimming. A pool water treatment can provide a full range of services, from testing and balancing your pool’s chemistry to treating any existing issues, providing a pool shock treatment, or fixing cloudy water.

They will also give you the advice you need on how to properly maintain your pool in the future, and how to best use pool equipment and chemicals like chlorine products safely and effectively.

If you have any questions or concerns about your swimming pool’s chemicals, don’t hesitate to contact a professional and let them take care of it for you. This will ensure complete peace of mind over your pool chemistry.

So – what chemicals does a pool need?

So, with all of the above in mind, which swimming pool chemicals will need to be added to your pool to maintain a perfect balance?

  1. The first chemical you need to maintain your pool is chlorine. Chlorine kills bacteria and other microorganisms, helping keep the water clean and safe for swimming. You can add chlorine in a variety of forms, such as chlorine tablets, chlorine granules, sticks, or liquids. You can also get chlorine reducers to help when chlorine levels are too high.
  2. Next up, if your alkalinity levels are low, you may need a total alkalinity increaser to raise it back up to the right levels. This chemical is typically made of sodium bicarbonate (baking soda) and helps to keep pH levels stable, just make sure to stick to the manufacturer’s guidelines.
  3. Another chemical you may need to add to your pool is a pool flocculant. If your pool chemistry is off, you may find that the water becomes cloudy or murky. Pool flocculants help to bind together dirt particles, making them easier to filter out of your pool.
  4. You may need also a pool stabiliser to make sure your chlorine levels don’t drop too low. These are often made with cyanuric acid, a chemical that helps protect chlorine from being broken down by the sun’s UV rays.
  5. If ammonia is present in your pool, you may need to add an ammonia remover to get rid of it. This chemical binds with the ammonia and makes it easier to filter out.
  6. Finally, if calcium hardness levels are too low, you may need a calcium hardness increaser. This product often uses calcium chloride, which helps raise CH levels back up to their ideal range. 
  7. Similarly, a pH increaser can be used to boost pH levels if they drop too low and a pH decreaser if they are too high. 
  8. If algae growth is found in your pool, we recommend shocking your pool with Granular Shock – or Algimax Eliminator for stubborn algae. Additionally, you can prevent algae growth with an algicide or algae controller.

With these chemicals to hand, plus an ongoing swimming pool maintenance schedule, you’ll be well on your way to creating a safe and enjoyable swimming environment.

Additional pool chemicals that are useful to understand

Summerclear

Blue Horizons Summerclear is a long-life copper-free algaecide used to prevent algae growth.

Summerclear is usually added to the pool just after spring commissioning and then dosed every three months thereafter. It has wide product compatibility and can be used in chlorine, bromine, and biguanide-treated pools. Remember, algae prevention is always better than cure.

In addition to this product, the smartest choice is to opt for a Summerize Pool Recommissioning Service, in which pool professionals will test, inspect, and recommission your pool to create a perfect setup ahead of pool season – and ensure that this Summerclear product is used correctly.

Ultimate Winter Time

Blue Horizons Ultimate Winter Time is a long-life copper-free algaecide formulated to prevent algae growth during the late autumn, winter, and early spring in outdoor swimming pools. One dose will help prevent algae growth for up to six months. 

Ultimate Winter Time also helps to minimise the likelihood of stains and scale deposits during the closed season, so it’s always a great chemical to pick up if you plan on decommissioning for the colder months.

Another great option is to go for a Winterize Pool Decommissioning Service, where experienced professionals can dose your pool with the required products and adequately prepare it for the upcoming season.

Closing thoughts

In summary: it is essential to regularly test your pool’s water chemistry in order to ensure that the levels of free chlorine, pH, ammonia, total alkalinity, and calcium hardness are within their ideal range.

While you can do this at home with testing strips and kits, a professional pool water treatment or assessment is the best way to ensure that your pool is really safe for swimmers.

With the right experts on hand, you can have true peace of mind knowing that your pool chemicals are properly maintained and that everyone can enjoy it without worry or concern. Plus, with regular maintenance and testing, you can enjoy swimming in crystal-clear water all summer long! Find out more about our ongoing pool maintenance services today!

Pool chemicals FAQs

What chemicals do I need for my above-ground pool?

The same chemicals are required for both above-ground and in-ground pools: chlorine, alkalinity increaser, pool flocculant, stabilizer, ammonia remover (if needed), calcium hardness increaser (if needed), and a pH increaser.

What chemicals do you add first when opening a pool?

When opening a pool for the season, it is important to start with chlorine and an alkalinity increaser. Next, you should check and adjust pH levels as needed. Finally, you should add other necessary chemicals such as a stabilizer, pool flocculant, or ammonia remover if required. Remember, don’t handle any chemicals that you aren’t familiar with. Always follow the manufacturer’s directions.

Are pool chemicals dangerous?

Whether or not pool chemicals are dangerous depends on how they are handled and used. It is important to always read and follow the manufacturer’s instructions when handling any chemical, including chlorine, alkalinity increaser, stabilizer, and other pool chemicals. Additionally, be sure to store these chemicals in a safe place, away from children and pets.