How to Raise Cyanuric Acid Levels In Your Pool

Written by Michael Dean
September 14, 2023

raising cyanuric acid in swimming pool

Cyanuric acid is a white and odorless mild acid that protects your chlorine from the sun’s harsh UV rays. Also known as CYA, or pool conditioner, its main purpose is to stabilize and lengthen the lifespan of the chlorine in your pool, effectively keeping the water cleaner for a longer period of time. But what happens when the levels of cyanuric acid drop? There are various reasons this could occur and several steps you can take to restore the cyanuric acid levels to ideal levels in your pool.

It’s handy to understand the science behind the chemicals you put in your pool, so let’s look at why cyanuric acid levels could drop in your pool and what you can do to raise them again.


Main Takeaways

  • Low cyanuric acid can be caused by dilution, backwashing, using unstabilized chlorine, or splashout.
  • If CYA levels are too low, you risk algae infestations, weak chlorine sanitization, and imbalanced pH levels.
  • You can raise CYA levels using two methods: 1) adding pure cyanuric acid or 2) using stabilized chlorine.
  • Maintain the right CYA levels by regularly testing the water, using a pool cover, and avoiding overusing other chemicals.

What Causes Low Cyanuric Acid?

There are various reasons why cyanuric acid levels in a pool could occur. Here are the most common reasons:

Dilution

Sometimes, adding fresh water to a pool is necessary to balance out other chemicals, such as calcium, but keep in mind that adding too much fresh water to the pool will most certainly lower the cyanuric acid levels, not to mention other chemicals as well. This dilution could also occur due to rainwater, so it’s best to note the weather patterns in your area and protect your water accordingly to avoid losing CYA because of excess (and potentially unfiltered) water.

Backwashing

Backwashing and cleaning your pool filter equipment is an absolute must, but doing so has the unintended side effect of some of the water and chemicals getting discharged, which can lower the cyanuric acid levels in your pool.

Using Unstabilized Chlorine

Sometimes, chlorine itself can lower cyanuric acid levels in the pool. Using unstabilized chlorine causes the chemical to transform into sodium hypochlorite ions, which can degrade quickly in sunlight. This causes the chlorine to bind aggressively with the cyanuric acid to stabilize, lowering the CYA levels significantly.

Splashout

Cannonballing into the pool might seem like harmless fun, but it can incrementally lower the levels of CYA in the water. People and animals jumping too frequently or violently into the pool can cause too much water to splash out, affecting cyanuric acid levels.

What Happens If Your Cyanuric Acid Levels Are Too Low?

The recommended range for cyanuric acid in your pool falls between 30 – 50 ppm (parts per million). Anything lower, and you will likely see several undesirable issues regarding your water chemistry.

Increased Chlorine Demand

Without enough cyanuric acid to stabilize the chlorine, you will need more chlorine to maintain the appropriate levels. You might be tempted to shrug your shoulders and immediately pour more chlorine into the pool, but just thoughtlessly adding more is not an effective or permanent solution.

Reduced Effectiveness of Chlorine

Low cyanuric acid levels invariably mean low chlorine levels since the CYA won’t be around to protect the chlorine from the sun. Unfortunately, this also means the chemical will be less effective in killing unwanted bacteria and algae in a pool.

Increased pH Levels

Low cyanuric acid levels can increase pH levels, which can cause the water to become cloudy and make it challenging to maintain proper chemical balance, leaving your water at risk for algae bloom infestation. Further, the resulting imbalance in water chemicals due to low cyanuric acid levels can indirectly lead to the corrosion of metal parts in the pool, such as heaters, pumps, or propellers.

Step-By-Step: How To Raise Cyanuric Acid In Your Pool

There are two different methods to raise cyanuric acid levels in your pool: using cyanuric acid or using stabilized chlorine.

Method One: Using Cyanuric Acid

Step One: Test the Water

First things first, you need to calculate how much cyanuric acid needs to be added to your pool. Test your water to gauge how much CYA is in the water already, then calculate the volume of water in your pool. Use my pool stabilizer calculator to help you.

Keep in mind that the amount required might also differ based on the brand used, so as always, read the instructions before calculating anything.

I recommend this testing kit to most of my clients (just in case you don’t have one yet).

Taylor High Range Swimming Pool Test Kit

This expansive test kit includes nine tests for most pool chemical measurements you need.

View on Amazon View on Walmart
I may earn a commission if you make a purchase, at zero additional cost to you. This in no way impacts my research process or opinions.

Step Two: Add the Cyanuric Acid

Add the cyanuric acid to your pool. If you’re using granular CYA, you could use a skimmer sock to disperse the chemical by placing it into the skimmer or over the return jet. You could also premix the granules in a 5-gallon bucket and pour it carefully into the skimmer for even dispersion.

If you’re using liquid cyanuric acid, simply pour the solution directly into the skimmer. Remember, it’s more sensible to add small amounts over time. It’s easier to add more cyanuric acid than it is to lower the levels in your pool.

Pool Mate Swimming Pool Stabilizer and Conditioner

Stabilizer is just a fancy name for cyanuric acid. Pool Mate makes a good product that is affordable.

View on Amazon
I may earn a commission if you make a purchase, at zero additional cost to you. This in no way impacts my research process or opinions.

Step Three: Turn on the Pump

Switch your pump on. Now it’s time for the filter to circulate the water to disperse the CYA throughout the pool. If the acid is granular, let the pump keep running for around 48 hours, but if liquid, you only need to leave the pump running for 4-5 hours.

Step Four: Retest the Water

Retest the water to check for CYA and chlorine levels. Repeat if necessary.

Method Two: Using Stabilized Chlorine

Step One: Test and Balance the Water

Start by balancing and testing your pool water, and then use my chlorine calculator to determine how much stabilized chlorine you’d need to add to the water for it to reach 1-3 ppm.

Step Two: Add the Chlorine

Measure the amount needed and dissolve the granules in a 5-gallon bucket of pool water. Once dissolved, walk the perimeter of your pool while steadily pouring in the solution.

Step Three: Turn on the Pump

Turn your pump on for the next 12-24 hours to circulate and filter the stabilized chlorine. You must avoid using the pool during this time, at least until the water has been cycled through the filter at least once, or you risk unpleasant side effects on your skin or in your eyes.

Step Four: Retest the Water

Retest the water to check for CYA and chlorine levels. Repeat if necessary.

How To Maintain The Right Cyanuric Acid Levels

Here are my top tips for maintaining the proper cyanuric acid levels in your pool.

Test the Water Regularly

Test your pool water regularly, at least once a week, to ensure the cyanuric acid levels are within the recommended range of 30-50 ppm.

Use a Pool Cover

If you live in a tropical area with high amounts of rainfall, use a pool cover to protect your water from the subsequent excess of water that may upset the cyanuric levels in the pool. This also applies to areas with heavy sunshine. Pool covers are essential for good pool maintenance!

Monitor the pH Levels

I can never stress enough how you must constantly monitor the pH levels of your pool. Fluctuations in pH levels can cause the cyanuric acid to become less effective (not to mention the other chemicals in your pool), so it’s essential to keep it in the recommended range of 7.2 – 7.6.

Use Algaecides and Other Chemicals as Directed

Algaecides and other chemicals can easily affect the cyanuric acid levels in your pool. Check the manufacturer’s instructions and use the chemicals according to the guidelines to avoid overuse or misuse.

By following these steps, it’s not that hard to maintain the cyanuric acid levels in your pool and ensure that your water is clean and sanitized for a fun swim session.

If you have questions, don’t hesitate to get in touch! I’m happy to answer any questions you may have.

Get My Free Pool Care Checklist

Download my free, printable pool maintenance checklist to help you accomplish regular pool care tasks for any type of swimming pool.

Something went wrong. Please check your entries and try again.
Scroll to Top