How to Use Cyanuric Acid in Your Saltwater Pool

Written by Michael Dean
March 4, 2023

adding cyanuric acid to a saltwater pool

Contrary to popular opinion, saltwater pools also use chlorine. And as with a traditional chlorine pool, you’ll need to maintain the longevity of this chlorine to keep the water sanitized for longer periods of time. To do this, you need cyanuric acid (CYA), also called a pool stabilizer.

In this article, I will explain why you need CYA in your saltwater pool and why and how to use this chemical.

Main Takeaways

  • Cyanuric acid in a saltwater pool protects the chlorine the saltwater generator produces, maintains water quality, improves clarity, and prevents algae growth.
  • The recommended levels for CYA in your saltwater pool are higher than for traditional chlorine pools: 60 to 80 ppm.
  • To lower CYA levels, do a partial drain and refill of the water based on the amount that has to be removed and the amount of water in the pool.

Do I Need Cyanuric Acid in My Saltwater Pool?

All swimming pools benefit from adding some CYA, including saltwater pools. Here are the main reasons why you need cyanuric acid in your saltwater pool maintenance routine.

It Protects and Stabilizes Chlorine

Saltwater pools generate chlorine through a process called electrolysis, but this chlorine that is generated breaks down in the sun’s UV rays. Cyanuric acid helps stabilize the chlorine in the water, preventing the free chlorine from being destroyed before it can sanitize the water.

It Reduces Chlorine Loss Due to Sunlight

And since cyanuric acid helps to reduce the amount of chlorine needed to maintain proper sanitation levels, this will save you more money and time spent on maintaining proper chlorine levels.

It Prevents Algae Growth and Promotes Clarity

Cyanuric acid can prevent algae growth by stabilizing the chlorine in the water. So your pool will be sparkling and blue instead of cloudy.

How Much Cyanuric Acid Do I Need in my Saltwater Pool?

Recommended cyanuric acid levels for a salt pool fall between 60 to 80 ppm (parts per million), which is higher than recommended for a chlorine pool. This is because saltwater generators produce chlorine at a slow pace. This makes it more difficult for the pool to maintain adequate chlorine levels on hot and sunny days. As a result, your chlorine would naturally need more protection than normal, which means adding a bit more CYA than one would for traditional pools, but try not to go over 100 ppm! Check out my pool salt calculator for an easy way to calculate how much salt you need.

When to Add Cyanuric Acid to a Saltwater Pool

It’s best to add CYA after you have recently balanced your water chemistry, especially during pool season. Once you’ve added all your chemicals, including chlorine, let the water circulate for about an hour, then check the water for cyanuric acid levels. This is because your other chemicals (algaecide and chlorine, for example) may already contain stabilizer—you don’t want to double dose if you can help it!

Keep in mind that cyanuric acid does not evaporate from the pool like other chemicals, so it’s critical to monitor its usage carefully and not overuse it. Adding too much cyanuric acid can lead to a buildup that makes the pool water less effective at sanitizing or even cause cloudy water. Remember: the ratio of free chlorine shouldn’t be less than 5% of your pool stabilizer levels.

How to Add Cyanuric Acid to a Saltwater Pool

Adding cyanuric acid to a pool is a relatively simple process that can be completed by following a few basic steps. Here’s a quick breakdown of how to add cyanuric acid to a pool.

Step One: Test and Calculate

Use test strips or a liquid test kit to check the current levels of CYA and chlorine in your pool, then calculate the amount of CYA you would need to add for it to be effective based on the current levels present and the amount of water in your pool.

Step Two: Add the Cyanuric Acid

Cyanuric acid is available in both granular powder and liquid forms. If using the former, premix the measured amount in a 5-gallon bucket of warm water, then pour the solution slowly into the pool, spreading it out evenly around the perimeter. If using a liquid form, simply add the measured amount directly into the water or your pool skimmer and let it circulate for the next few hours.

Step Three: Retest the Water

After the cyanuric acid has had time to dissolve, retest the water to ensure the level is in the recommended range. You may need to add more cyanuric acid if it’s too low. If it’s too high, you may need to partially drain the pool and refill it with fresh water.

How to Lower Cyanuric Acid Levels in a Saltwater Pool

If you have accidentally overdosed your pool with CYA, don’t worry! Here are the steps to get the CYA levels down to the recommended levels.

Step One: Drain and Refill the Pool

Use a submersible pump or a store-bought hose siphon to drain your pool. If your filter has the ability, it could also be set “drain” to siphon the water out of the pool without you doing any work. Oversee the drainage carefully, and drain only around a few inches at a time between refills. You need to be careful not to go below your pool skimmer, or your pump might run short, causing it to malfunction.

Step Two: Retest the Water

Once you’ve drained enough water and refilled the pool, retest your CYA levels. Make any adjustments if necessary. Continue draining and refilling your water until you reduce cyanuric acid levels to the normal range for saltwater pools, between 60 to 80 ppm.

Step Four: Monitor Your Pool Levels

Keep an eye on the cyanuric acid levels in your pool regularly. This will ensure that the levels remain within the recommended range and that the pool water is safe for swimming. In fact, it’s best to add a cyanuric acid test strip to your weekly routine of testing water chemistry to avoid the hassle of draining and refilling. And as it is much easier to add CYA than lower it, take care when adding stabilizer to your pool.

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How Soon Can I Swim After Adding Cyanuric Acid to My Saltwater Pool?

I generally recommend waiting at least 12 to 24 hours after adding cyanuric acid to a saltwater pool before swimming. This allows time for the chemical to mix evenly throughout the water, which is needed since cyanuric acid can take some time to dissolve, especially if it’s added in granular form. Undissolved granules could cause skin or eye irritation, so it’s best to wait a bit before jumping in.

Questions about cyanuric acid and saltwater pools? Let me know.

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