What is the definition of "shock treatment" in pool management?

Shock treatment refers to the process of adding a significant dose of chlorine to the pool water to eliminate contaminants, such as bacteria, algae, and organic matter. This method is essential for maintaining water quality and ensuring a safe swimming environment. By increasing the chlorine level temporarily, shock treatment helps to oxidize and break down chloramines, which are compounds that can cause unpleasant odors and irritate the skin and eyes.

This treatment is especially useful after heavy pool usage, following a rainstorm, or when water clarity becomes an issue. The elevated chlorine level ensures that harmful microorganisms are effectively killed off, restoring the pool's hygiene and clarity.

The other options do not relate to the concept of "shock treatment" in the context of pool management. Testing water clarity is a routine monitoring process, lowering water hardness pertains to managing calcium levels in the pool, and emptying and cleaning the pool is a more drastic maintenance action that does not reflect the core function of shock treatment.