What does the term "backwashing" refer to?

The term "backwashing" specifically refers to the process of reversing the flow of water through a filter in order to clean it. During backwashing, water flows backward through the filter media, dislodging trapped debris, contaminants, and dirt. This process ensures that the filter maintains its effectiveness and continues to function properly, as a clean filter is essential for maintaining water clarity and quality in a pool.

While filtering out contaminants is an essential function of the pool filter, backwashing itself is a maintenance technique to ensure that the filter continues to work efficiently. Adding chemicals to balance pH pertains to water chemistry management but is unrelated to the filtering process. Draining the pool is part of pool maintenance but does not correlate with the concept of cleaning the filter. Thus, the definition of backwashing is correctly tied to the action of reversing water flow to enhance the filtration system's performance.