In the absence of accessibility of other methods of purifying water, a very cheap method which can be used at home to cut water costs is use of sunlight to sterilize water. Sunlight has UV rays which are not conducive to the growth of pathogens. Simply put the water into a transparent tub and place it in sunlight for the UV pays to penetrate. Sunlight at any intensity contains UV rays. The tub containing the water should be placed in am open place or on the roof for at least 6 hours.