Everything You Want to Know About Cyanuric Acid Levels and Why It Is Important

Want to know more about cyanuric acid? Here’s a detailed article that covers everything you need to know about cyanuric acid levels and how they affect your pool.

Cyanuric acid (a.k.a pool stabilizer) is a chemical that helps to balance chlorine and keeps it strong even when the temperature changes. When your cyanuric acid levels are correct, you’ll have a beautiful pool that takes care of itself and maintains stability throughout the seasons.

But when your cyanuric acid gets too high, bad things can happen. 

If you’re wondering how to lower your cyanuric acid levels or just want to get an idea of where they should be set for optimal safety, this post has you covered!

Testing Kit

With all these helpful tips and tricks, you’ll be able to find out the optimal levels of CYA, how to test your pool, and of course, how you can increase and decrease CYA levels in your pool when you need to. Plus, a lot more information about CYA that will help you maintain a healthy pool.

So let’s swoop in and learn the ins and outs of cyanuric acid in your swimming pool today!

What is Cyanuric Acid?

The cyanuric acid (also known as triazole-thiocyanate) is a chlorine-based compound used as a water purifier. A lot of the time, many pool owners use CYA for their swimming pools because it’s been successful in keeping the pool clean.

Cyanuric acid combines with chlorine molecules to form new compounds that are more stable and less likely to break down. This means that they will be better at fighting against bacteria and other contaminants before they can cause any problems for swimmers or get out of control themselves.

CYA also helps prevent the loss of free chlorine, which helps keep your pool clean and safe for you, your family, and your friends!

There are many different ways to make sure that your pool is properly maintained and kept clean. One of the most effective ways, however, is to add cyanuric acid to the water.

How Does Cyanuric Acid Work?

This substance helps form a chemical reaction between chlorine and hydrogen peroxide. This new compound, once formed, will prevent the chlorine from breaking down too fast.

What this does is protect your pool’s chlorine from wearing out too quickly. Without chlorine, your pool will soon lose all of its effectiveness.

Not only do these chemicals have significant roles, but they also have lots of different uses! For example, by adding them to your swimming pool, you can keep it clean and safe for swimmers.

Why Having a High Cyanuric Acid is Bad News?

When cyanuric acid levels become too high, it might result in a condition known as chlorine demand or chlorine lock, which essentially indicates that your chlorine has been made ineffective by the acid.

Chlorine Testing Kit

The only way to identify whether this has happened is if your chlorine test reveals little or no chlorine present, even after you have added chlorine to the pool.

Moreover, having a high concentration of CYA in your pool water can cause several problems, including; 

  • Unable to correctly measure your pool water’s alkalinity level. High CYA levels can alter your alkalinity readings because they mimic the pool’s total alkalinity (carbonate alkalinity).
  • Reduce chlorine potency. High levels of CYA in your pool weakens the effectiveness of pool chlorine, keeping it from doing its job. Precisely called chlorine demand, this happens because CYA overthrows the free chlorine in your pool.

    Unbalance chlorine and pool chemistry soon leads to algae growth and cloudy water.
  • Damage plaster. High CYA usually means a low pH level in your pool because of the ineffectiveness of chlorine. Low Ph levels may result in your plaster degrading because water will gradually consume it away.

    Sure, damaged plaster can be fixed, but it will require you to drain your entire pool.
  • Lesser ORP readings. The ORP (oxidation-reduction potential) of water is a measurement of its oxidizing ability. When there is an excessive CYA present, you will notice a drop in the ORP as chlorine becomes inefficient.
  • Health problems. A high CYA concentration can negatively influence your health because it prevents the removal of a harmful organism known as cryptosporidium parvum from the water. This organism has the potential to infect the gastrointestinal system of swimmers, producing digestive problems and diarrhea.

How to Check for Cyanuric Acid Levels in the Pool

testing cya levels using kit beside pool

There are two easy approaches to check for cyanuric acid levels in the pool: one is with test strips, and the other is with a kit.

The test strips are the quickest, easiest, and least expensive way to test cyanuric acid levels. You can get these test strips at your local pool store.

Just dip the paper strip in your pool water, matching the color chart on the side of your test strip bottle to know how much cyanuric acid is present in your water. This is not as accurate as a kit but is good enough for a basic check.

The other method to check for cyanuric acid levels is with a kit that you can buy online or in local stores like Home Depot. You can also have the pool tested at a local pool store.

Kits are more accurate and give you more information than test strips. The kit usually comes with a bottle that you can add 5-10 drops of water to (per the kit instructions), cap it, and shake.

You then place the bottle in a bit of a container with chemicals that cause the liquid to change colors based on what is in your water sample, revealing how much cyanuric acid is present in your swimming pool.

Either way, you’ll know the answer, and you can decide whether to lower or leave your cyanuric acid levels alone.

What Are the Appropriate Cyanuric Acid Levels in a Pool?

The World Health Organization proposes a maximum concentration of cyanuric acid in a swimming pool of 100 parts per million (ppm). They reached this number based on the assumption that kids will almost certainly swallow some water when swimming and that if they consume too much CYA, it can cause harm to their health.

Aside from health purposes, we recommend keeping cyanuric levels at around 50 ppm; any higher will provide a thriving environment for bacteria and algae growth.

How to Reduce Cyanuric Acid Levels in a Pool

If you test your pool water and discover that the CYA levels are too high, the first step is to investigate the problem.

You should know that using stabilized chlorine adds small amounts of CYA to your pool. To see if your chlorine contains cyanuric acid, look for these labels;

  • Potassium dichloroisocyanurate
  • Sodium dichloroisocyanurate
  • Trichloroisocyanurate

If one of these chemicals matches your chlorine labels, then it’s advisable to switch to non-CYA chlorine to prevent levels from rising again.

Still, you need to lower the level of CYA, and the only way to do this is by diluting your water. First, splash out your water level, then add fresh water to your pool. However, if the CYA is way above the roof, you may need to drain your pool water entirely and refill it with fresh water.

High-level CYA usually gets stuck in your filtration system, so make sure to clean or change your filter.

How to Increase Cyanuric Acid Levels in the Pool?

Low cyanuric acid levels are typically not an issue because even small amounts of CYA can help extend chlorine life in your pool.

But to increase cyanuric acid levels in a pool, owners may simply add some cyanuric acid granules according to the manufacturer’s recommendations.

Pool owners usually use cyanuric acid as an additive to chlorine tablets and are directly thrown in a pool to increase chlorine effectiveness; they often referred to this process as a “booster.”

Learning how to reduce cyanuric acid levels in the pool requires some effort at first, but once you get the hang of it, it’s not that difficult. While cyanuric acid is a vital component for keeping chlorine active for a more extended time, remember that too much CYA will weaken chlorine, making it less efficient in killing harmful bacteria and viruses.

On the other hand, by maintaining the proper CYA and chlorine levels, you’ll have a huge chance to win the battle of algae and bacteria contaminating your pool in any climate condition. That’s something worthy of your consideration!

Read more about cyanuric acid and how to keep your pool sanitize and safe. Have fun and enjoy swimming!

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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