What is the primary objective of adding chlorine to water?

The primary objective of adding chlorine to water is to sanitize it, which means that chlorine is used to kill harmful bacteria, viruses, and other pathogens that can pose health risks to swimmers. This sanitization process ensures that the water remains safe for human contact, which is crucial in pools, hot tubs, and other recreational water venues.

Additionally, chlorine plays a significant role in preventing the growth of algae. Algae can proliferate quickly in warm, stagnant water, leading not only to unsightly green water but also to potential safety hazards due to slippery surfaces. By maintaining adequate levels of chlorine, both the sanitation of the water and the control of algae growth are effectively managed.

Thus, the correct answer encompasses both the sanitizing purpose of chlorine and its role in algae prevention, combining them into a single response. This understanding is fundamental for any pool operator aiming to manage water quality effectively.