A cheap filter which any tinner can make is 12 x 6 inches in size, and 8 inches high. The water flows in near the top, and on the top is a door through which to get into it to clean it. The outlet pipe at the bottom projects 2 inches up on the inside to hold the dirt back. A large sponge is placed inside, which forms the filtering medium, which, of course, can be cleaned as often as desired. The place of the sponge may be taken by powdered charcoal placed in a cotton bag.