Which chemical is known for its ability to stabilize chlorine in sunny outdoor pools?

Cyanuric acid is recognized for its ability to stabilize chlorine in sunny outdoor pools. When chlorine is added to pool water, it is prone to degradation by ultraviolet (UV) light from the sun. This degradation can significantly reduce the effectiveness of chlorine, leading to inadequate disinfection and potential safety issues for pool users.

Cyanuric acid acts as a stabilizer by forming a protective bond with chlorine, which shields it from UV degradation. When cyanuric acid is present in the water, it helps maintain a more consistent level of free chlorine over time, ensuring that the pool remains properly sanitized even in bright sunlight. This characteristic makes it an essential component for outdoor pool maintenance, especially in regions with high sun exposure.

In contrast, while chlorine is necessary for sanitation, it is not a stabilizer. Ozone is a powerful oxidizer that can disinfect water but does not provide the same stabilization effect for chlorine. Calcium hypochlorite is a common form of chlorine used for pool sanitation but also lacks the ability to stabilize chlorine in the presence of sunlight.