Abstract: A method for killing water borne microorganisms comprises reacting two electrolytically-reactive elemental metals in water to dissolve sufficient metal ions to kill algae and coliform bacteria, without making the water unsafe for human use. Lead, copper and zinc are examples of such metals. Apparatus for performing the method comprises a perforated container of chips of such metals. A small version of the device can be used in toilet reservoirs to prevent the growth of microorganisms within the toilet bowl. A larger version of the device, submerged in a swimming pool, effectively prevents the growth of algae or coliform bacteria, substantially reducing or eliminating the need for chlorine. One embodiment of the device has an elongated cylindrical container with perforated side and bottom walls and a hook at its upper end for suspending the device in a swimming pool or toilet reservoir.

Abstract: A device for killing moss on rooftops comprises an elongated bimetallic trough for horizontal positioning along a rooftop to catch rainwater. In one embodiment the walls of the trough include a layer of copper and a layer of lead sandwiched together. Small holes through such layers, and spaced apart in rows along a wall of the trough, slowly drain the rainwater onto the rooftop. As the water passes through the holes, contacting the junction of the lead and copper layers, an electrolytic action occurs in which ions of the metal dissolve into the water. The resultant electrolyte kills the moss. Another embodiment comprises a plastic trough having holes in one side and containing pieces of lead and copper.