What are polyphosphates, including sodium hexametaphosphate, commonly used as?

Polyphosphates, such as sodium hexametaphosphate, are primarily recognized for their role as sequestering agents. Sequestering agents are substances that can bind to metal ions, preventing them from participating in unwanted reactions, which is particularly valuable in water treatment processes. By sequestering calcium, magnesium, and iron ions, polyphosphates help to inhibit scale formation, reduce water hardness, and improve the efficiency of other treatment chemicals.

Their ability to stabilize and control the chemistry of water makes them essential in various applications, including preventing corrosion and improving the effectiveness of disinfectants. While they can contribute to the overall operation of water treatment facilities, their main function lies in their ability to maintain clarity and enhance the quality of the treated water by mitigating the impact of metallic impurities.