Why is cyanuric acid added to pool water?

Cyanuric acid is added to pool water primarily to stabilize chlorine and reduce its degradation from UV light. When chlorine is exposed to sunlight, it can break down quickly, diminishing its effectiveness in disinfecting the water. By adding cyanuric acid, which acts as a stabilizer or conditioner, the chlorine remains active for a longer period. This stabilizing effect is particularly beneficial in outdoor swimming pools where sunlight exposure is significant.

On the other hand, the addition of cyanuric acid does not directly soften water, contribute minerals, or enhance pH balance. While maintaining a proper pH level is crucial for pool chemistry, cyanuric acid specifically serves the purpose of prolonging chlorine effectiveness in the presence of sunlight. This is why it is considered essential for maintaining water quality in outdoor pools.