Abstract: This invention relates to a process for disease control in fish farming and more particularly, to a process whereby proliferative gill disease and other diseases and infections are eliminated by the treatment of a fish rearing pond or tank with low concentrations of Chloramine-T. The Chloramine-T is applied to the pond or tank and allowed to remain in the tank or pond until it breaks down. The concentration of the Chloramine-T can be from about 2 to about 3 PPM.