Which of the following is a common type of pool sanitizer?

Chlorine is a common type of pool sanitizer because it effectively kills bacteria and other harmful microorganisms in pool water. When chlorine is added to the water, it undergoes a chemical reaction that produces hypochlorous acid, which is the active form of chlorine that can effectively sanitize the water. Chlorine not only eliminates pathogens but also helps in controlling algae growth and oxidizing organic matter, thus maintaining clear and safe swimming water.

In contrast, while salt can be used in saltwater pools to generate chlorine through a process called electrolysis, it is not a sanitizer itself. Algaecide is designed to prevent and control algae but does not provide a comprehensive sanitizing solution for bacteria and pathogens. Flocculant is a chemical used for clearing cloudy water by agglomerating suspended particles, but it does not function as a sanitizer. Therefore, chlorine stands out as the primary chemical widely recognized for its sanitizing properties in pool maintenance.