A method of controlling the growth of bacteria and algae in utilitarian bodies of water such as industrial cooling towers, swimming pools and hot tubs is described. The method includes adding to the water trivalent copper compounds including the periodate and chelate complexes of biuret an tris-(hydroxymethyl) aminomethane. These compounds meet EPA standards of killing 100% of select coliforms within 10 minutes and are efficacious at concentrations as low as 5-9 PPM.

A method for controlling the growth of bacteria and algae in utilitarian bodies of water such as industrial cooling towers, swimming pools and hot tubs is described. The method comprises adding to the water novel trivalent silver compounds. Said compounds are light stable and can be supplied as liquid concentrates which will not precipitate any silver whatsoever from saline waters nor will the concentrates stain skin or discolor surfaces. Said compounds meet the rigid EPA standards of killing 100% of select coliforms within ten minutes and are efficacious at concentrations as low as 1-2 PPM.

A novel molecular scale device is described which is bactericidal, fungicidal and algicidal. The antipathogenic properties of the device are attributed to electron activity indigenous to diamagnetic semiconducting crystals of tetrasilver tetroxide (Ag.sub.4 O.sub.4) which contains two monovalent and two trivalent silver ions in each molecular crystal. When the crystals are activated with an oxidizing agent, they release electrons equivalent to 6.4.times.10.sup.-19 watts per molecule which in effect electrocute pathogens. A multitude of these devices are effective at such low concentrations as 0.3 PPM where they can kill 100% of 100 K/cc Streptococcus faecalis, and E. coli colonies in three minutes meeting the ten-minute EPA criteria of 100% kills within ten minutes for swimming pool and hot-tub applications. The devices can be used in utilitarian bodies of water, such as municipal and industrial water reservoirs.

Divalent silver oxide provides a source for divalent bactericidal silver ions in the presence of persulfate. This oxide is especially effective when applied to water used in industrial cooling towers, hot tubs and swimming pools and conforms to stringent EPA requirements of 100% kills of 100K/cc Streptococcus faecalis within 10 minutes. The oxide also can be used in water with exceptionally high salt content without halide curdy precipitate formation and will not stain the skin of users who may inadvertently be exposed to it.

Solid bactericidal compositions are disclosed based on divalent silver (Ag(II)) as the active sanitized agent. The compositions are prepared by reacting acid liquid Ag(II) complexes with anhydrous calcium sulfate so as to form a solid matrix in which the bactericide is entrapped in the resulting hydrated calcium sulfate. Optimum compositions are described consisting of Ag(II) phosphate dissolved in phosphoric acid where the ratio of solid (by weight) to liquid (by volume) is 5:2. The resulting solid bactericides can be used in water cooling installations. They are capable of causing 100% kills within 10 minutes of E. Coli conforms in conformity with EPA protocols, allowing them to quality as swimming pool and hot tub sanitizers. Since the compositions are based on calcium sulfate, they are also suitable as mineralizers, thus providing a dual function.