What is the process called that reverses water flow to clean a sand filter?

The process that reverses water flow to clean a sand filter is known as backwashing. During the backwashing procedure, water is directed in the opposite direction through the filter media. This reversal dislodges and flushes out accumulated dirt, debris, and contaminants that have been trapped in the sand.

Backwashing is a critical maintenance step because it helps to restore the filter's effectiveness by ensuring that the flow of water can be unobstructed. As contaminants build up in the sand, the filter becomes less efficient, which can lead to reduced water clarity and potential water quality issues. By performing backwashing, pool operators can extend the lifespan of the filter and maintain optimal filtration performance, ensuring clean and safe pool water.

In contrast, the other options do not accurately describe the process used for cleaning sand filters. For instance, filter processing typically refers to the overall management of filtration systems rather than a specific cleaning process. Layered sand removal would imply physical removal of sand layers, which is not how maintenance is conducted in sand filters. Detergent recycling is unrelated to water filtration, as it pertains to the reuse of cleaning agents rather than a backwashing process. Thus, backwashing stands out as the appropriate term for this essential cleaning method in sand filter maintenance