The Aqua2use graywater system filters waste water from the washer, shower, and bath and channels it to the garden, saving a family of four roughly 40,000 gallons per year, the company estimates. The high volume of water dilutes the soap enough to benefit plants, and a four-stage purification filter removes lint and debris. The compact system installs above or below ground. Water Wise Group. 805.468.4920.