The volume of water going through a filter system is measured in which of the following units?

The volume of water flowing through a filter system is accurately measured in gallons per minute (GPM). This unit effectively captures the rate at which water is processed by the filter, providing essential data on the system's efficiency and performance. One of the primary reasons GPM is the standard measurement is that it relates directly to how much water is being circulated and filtered in a given period, which is critical for maintaining water quality in pool systems.

Other units, like pounds per square inch, measure pressure rather than flow rate, making them unsuitable for this context. Parts per minute isn’t a standard measure for flow rate in this scenario, and while cubic feet per hour could be considered for larger volumes, gallons per minute is more commonly used due to its practicality in typical swimming pool operations. Hence, gallons per minute is the most appropriate and widely recognized unit for measuring water flow through a filter system.