This is an Greywater is gently used water from your bathroom sinks, showers, tubs, and washing machines. It is not water that has come into contact with feces, either from the toilet or from washing diapers.
Builder's Gray Water Guide: gray water systems in new construction or remodeling. Includes gray water regulations, dealing with inspectors, legal requirements checklist, sample permit, treatment effectiveness studies.
This pin shows how a reed bed can be turned into a plant-based grey water system. The reed bed shares common features with the water bottle filter. There is gravel and sand in the reed bed that helps to filtrate that water.