Why High Cyanuric Acid (CYA) Levels Cause More Total Chlorine
High levels of cyanuric acid (CYA) can lead to an increase in total chlorine in the pool, primarily because of its effect on free chlorine and combined chlorine. Here’s a breakdown of how this works:
Why High Cyanuric Acid (CYA) Levels Cause More Total Chlorine
High levels of cyanuric acid (CYA) can lead to an increase in total chlorine in the pool, primarily because of its effect on free chlorine and combined chlorine. Here’s a breakdown of how this works:
1. CYA Stabilizes Chlorine, but Limits Free Chlorine:
Cyanuric acid acts as a stabilizer for chlorine by protecting it from UV degradation. In the presence of CYA, chlorine’s breakdown by the sun is slowed, meaning more chlorine remains in the water for longer. However, when CYA levels get too high, the chlorine becomes more "bound" to the CYA molecules, reducing the amount of free chlorine that is available to sanitize the water. As free chlorine levels drop, the effectiveness of chlorine in breaking down contaminants decreases.
2. Increased Combined Chlorine (Chloramines) Formation:
As chlorine becomes less available for sanitizing, contaminants like body oils, sweat, urine, and other organic matter accumulate in the pool. Chlorine reacts with these contaminants to form combined chlorine (chloramines), which are not effective at sanitizing the water and can lead to issues like pool odor or skin irritation. Since free chlorine is no longer available to handle these contaminants effectively, more of the chlorine in the pool is converted to combined chlorine.
3. Effect on Total Chlorine:
Total chlorine is the sum of both free chlorine and combined chlorine. When CYA levels are high, the amount of free chlorine in the pool decreases, and more chlorine ends up in the combined form, increasing the total chlorine measurement. This increase in total chlorine is often a sign that the pool has an insufficient amount of free chlorine available to deal with contaminants.
In Summary:
High CYA levels reduce the amount of free chlorine in the pool, leading to poor sanitation. As a result, more chlorine is consumed by contaminants, turning into combined chlorine (chloramines), which raises the total chlorine levels. This is why pools with high CYA often show an elevated total chlorine reading but suffer from poor water quality due to a lack of effective free chlorine.