What is the purpose of using a sequestering agent in a pool?

A sequestering agent serves the purpose of preventing the precipitation of minerals on the pool's surface. In pools, minerals such as calcium and magnesium can become concentrated and form scale or deposits when conditions change, such as variations in pH or alkalinity. By using a sequestering agent, these minerals are kept in a dissolved state, which significantly reduces the likelihood of them settling out and forming unsightly stains or scale on the surfaces of the pool and equipment.

While other choices may address different aspects of pool maintenance, they do not pertain specifically to the role of a sequestering agent. For instance, preventing algae growth typically involves the use of algaecides or proper sanitation measures rather than a sequestering agent. Stabilizing chlorine is achieved through the use of stabilizers such as cyanuric acid, which protect chlorine from degradation by UV light. Lastly, any aesthetic enhancement, like providing a tint of blue to the water, is not a function of sequestering agents, which are purely chemical treatments to manage mineral concentrations.