What is Cyanuric Acid?
In order to maintain a sanitary and hygienic pool, chlorine is used to remove bacteria or any living organism within the water. Two of the most common types of chlorine, tri-chlor (Tri-chloro-s-triazine-trione) and di-chlor (Sodium dichloro-s-triazinetrione), are used in modern pool commerce through tablet and granular form. Tablets are compressed for the intention of placing in a chlorinator or skimmer basket to allow a gradual introduction of chlorine as water flows across. Granular form is what most perceive as chlorine shock. The powdery substance is added directly to the deep end of the pool for immediate introduction of sanitation to the body of water. Each of these forms of chlorine is classified as Cyanurates, which means the substance contains the ingredient cyanuric acid.
In the early 1960s, scientific research has shown that cyanuric acid would help stabilize the chemical levels present in a body of water. Ultraviolet light has been proven to degrade the effectiveness of chlorine as a sanitizer, however with the addition of cyanuric acid, the effects of the sun’s rays have a minimal effect. The reduction of ultraviolet effects is often why cyanuric acid is also known as stabilizer. Due to chlorine being classified as a cyanurate, the substance has a minimal amount of cyanuric acid however over time the level of acid will continue to rise. The ideal level is between 30 to 50 parts per million, which should be tested regularly. Cyanuric acid levels above 70 to 80 parts per million will interfere with normal chlorine use and could develop chlorine lock. Chlorine lock is a condition where the water will turn cloudy and algae growth will begin to amplify, even if the water chemistry is balanced. The condition can also be very unhealthy for swimmers of all ages. High cyanuric acid levels can alter analysis of other chemicals necessary for pool sanitation.
If your pool has been diagnosed as having high cyanuric acid, discontinue the use of tri-chlor and di-chlor chlorine products. The best alternative is to switch to an unstabilized chlorine product, such as calcium hypochlorite caplets and shock. Another alternative is non-chlorine oxidizer (Potassium Monopersulfate). By discontinuing the use of stabilized chlorine products, the cyanuric acid level should subside over time. The quickest and most effective means of reducing cyanuric acid levels is to remove small quanities of water in two foot increments. For the most severe cases, up to one half of the pool water could be diluted. Cyanuric acid is a manageable issue if one would regularly test your water and switch chlorine variety as needed.