Cyanuric Acid: The Most Misunderstood Chemical in Pools

The Chemical That Pool Pros Love to Hate

Picture this: there's a chemical in your pool that could save you thousands of dollars in chlorine costs, but if you ignore it, it could completely cripple your sanitizer effectiveness and turn your customers' plaster blue. Sound too dramatic? According to pool industry veteran Rudy Stankwitz, this scenario plays out in backyards across America every day, and it all comes down to one widely misunderstood chemical: cyanuric acid.

So if I told you that there was a chemical in your pool that could save you literally thousands of dollars in chlorine, but at the same time, if you ignore it, could cripple your sanitizer effectiveness, could turn your plaster bluer than your balls were on prom night, and quietly push your water into corrosive territory while every test strip is lying to your face, telling you, hey, this shit looks good. You'd probably want to know what chemical I'm talking about, right?

— Rudy Stankwitz, Talking Pools Podcast

In a recent episode of the Talking Pools Podcast, Stankwitz tackles what he calls "the most misunderstood, misquoted, and overdramatized troublemaker in the entire swimming pool industry." For pool professionals and homeowners alike, understanding cyanuric acid isn't just about water chemistry—it's about economics, efficiency, and avoiding costly mistakes that can plague pools for months.

The Accidental Pool Hero: How CYA Found Its Purpose

Cyanuric acid didn't start its life as a pool chemical. Originally an industrial compound, it found its way into swimming pools when chemists realized chlorine had a major weakness: ultraviolet light from the sun was destroying it faster than it could sanitize the water.

Didn't start off as a pool chemical. No, no, no, no, no. It was just an innocent industrial compound minding its own business until some genius chemist said, Hey, chlorine keeps getting roasted by the sun. What if we gave it sunscreen?

— Rudy Stankwitz, Talking Pools Podcast

By the 1960s, CYA was being combined with trichlor and dichlor. By the 1980s, it was everywhere in the pool industry. But with widespread adoption came widespread confusion. The chemical that was supposed to solve problems started creating new ones—not because of what it did, but because of how people misunderstood what it did.

The science behind CYA is actually straightforward: it protects chlorine by forming chlorinated cyanurates, essentially acting as tiny bodyguards for the active chlorine (HOCl) that actually kills bacteria and algae. Without this protection, chlorine can be completely destroyed by sunlight in as little as 10 minutes.

The Economics of Stabilizer: Why Your Chlorine Budget Depends on CYA

Here's where the rubber meets the road for pool professionals: cyanuric acid directly impacts your bottom line. Stankwitz points out that without proper CYA levels, chlorine budgets can easily double. For service companies managing dozens or hundreds of accounts, this isn't just a chemistry issue—it's a business sustainability issue.

The economic impact works both ways:

• Too little CYA: Chlorine burns off rapidly in sunlight, requiring constant additions and driving up chemical costs
• Too much CYA: Chlorine becomes less effective, leading to algae problems, customer complaints, and expensive remediation
• Just right: Chlorine works efficiently, costs stay manageable, and pools stay clear

The challenge is that many pool professionals have been taught to fear CYA rather than manage it properly. This fear often leads to either avoiding it entirely (expensive) or not monitoring it closely enough (problematic).

Debunking the Myths: What You Think You Know About CYA

The pool industry is notorious for perpetuating myths, and cyanuric acid has collected more than its fair share. Stankwitz is particularly critical of outdated information that continues to circulate among pool professionals.

Cyanuric acid is not the problem. Misunderstanding cyanuric acid is the problem.

— Rudy Stankwitz, Talking Pools Podcast

One of the biggest myths involves the relationship between CYA and pH. Many pool professionals have been taught that these two chemicals interact in ways that complicate water balancing, but Stankwitz calls this "the pH fable you need to stop repeating."

Another persistent myth is that there's a magic number—often cited as 90 parts per million—above which CYA becomes dangerous. According to Stankwitz, this isn't based on chemistry but rather on the industry's lack of trust in technicians' ability to perform proper dilution tests for higher levels.

The reality is more nuanced: CYA levels need to be balanced against chlorine levels and managed based on actual pool conditions, not arbitrary industry standards that may not reflect real-world chemistry.

The Testing Trap: Why Your Test Strips Might Be Lying

One of the most dangerous aspects of CYA mismanagement is how it can hide behind normal-looking test results. Standard test strips can show balanced pH, adequate chlorine, and proper alkalinity while CYA levels climb to problematic heights.

This creates a false sense of security for pool professionals who rely heavily on quick tests. The water looks good, the basic chemistry appears balanced, but the CYA is quietly building up and reducing sanitizer effectiveness.

The problem compounds when using dichlor or trichlor products, which contain CYA. Every addition of these popular chlorinating chemicals adds more stabilizer to the water. Over time, this can create a situation where:

• Chlorine readings appear normal but effectiveness is reduced
• Algae problems become more frequent despite proper chemical readings
• Customer complaints increase about water quality issues
• More chemicals are needed to achieve the same results

The solution requires more sophisticated testing and a better understanding of how CYA interacts with other pool chemicals over time.

Practical CYA Management: Getting It Right in the Real World

So how do pool professionals properly manage cyanuric acid without falling into the common traps? Stankwitz emphasizes that it starts with understanding the chemical's actual function rather than following outdated industry rules of thumb.

CYA got popular because it works. It protects chlorine by forming chlorinated cyanurids. It's little tiny bodyguards keeping HOCL, which is the active form of chlorine, the killing form, from sunburning off in 10 minutes. Without CYA, your chlorine budget easily doubles. Too much CYA? Chlorine moves like it just ate two pounds of pasta fijo. With the right amount? Chef's kiss. Simple.

— Rudy Stankwitz, Talking Pools Podcast

Effective CYA management requires:

• Regular, accurate testing: Not just test strips, but proper testing that can handle higher CYA levels
• Understanding chlorine-to-CYA ratios: The relationship between these chemicals is more important than individual levels
• Monitoring chemical additions: Every dichlor or trichlor addition affects CYA levels
• Customer education: Pool owners need to understand why CYA matters and how their chemical choices affect it
• Seasonal adjustments: CYA needs change with sun exposure, pool usage, and weather patterns

The key is moving beyond fear-based decision making to chemistry-based management. This means understanding what CYA actually does, how to test for it properly, and how to maintain it at levels that optimize chlorine effectiveness without creating problems.

The Bottom Line: Making Peace with Pool Chemistry

Cyanuric acid will likely remain controversial in the pool industry because it requires nuanced understanding rather than simple rules. But for pool professionals willing to move beyond the myths and master the chemistry, it represents an opportunity to provide better service, reduce costs, and solve problems that plague many pools.

The irony is that CYA was developed to solve a problem—chlorine degradation from UV light—and it does that job extremely well. The problems arise not from the chemical itself, but from decades of misunderstanding, incomplete education, and industry practices that prioritize simplicity over accuracy.

As Stankwitz points out, the pool industry has been arguing about CYA for decades while the chemistry has remained constant. Perhaps it's time to stop fighting the chemical and start understanding it. For pool professionals, this understanding can translate directly into more efficient operations, happier customers, and better business results.

The most misunderstood chemical in pools doesn't have to stay misunderstood. With proper education, testing, and management practices, cyanuric acid can fulfill its original purpose: making pool maintenance more efficient and effective. The question isn't whether to use CYA, but how to use it correctly.

Episode Chapters

• 00:00 Introduction and Breaking News
• 15:30 The Cyanuric Acid Mystery
• 22:15 Origins and History of CYA
• 28:45 Common Myths and Misconceptions
• 35:20 Testing Problems and Hidden Issues
• 42:10 Practical Management Strategies