Patent attributes
The invention provides a bactericidal/algicidal method including adding an oxidant-based bactericidal/algicidal agent and a stabilizer therefor to a target water system, characterized in that the amount of combined chlorine or the stabilizer in the water system is controlled by generating free residual chlorine in the water system, and a bactericidal/algicidal method including adding an oxidant-based bactericidal/algicidal agent and a stabilizer therefor to a target water system, characterized in that the amount of the oxidant-based bactericidal/algicidal agent added is controlled so that the concentration of total residual chlorine in the water system falls within a predetermined range, and the amount of combined chlorine or the stabilizer is controlled so that the concentration of free residual chlorine in the water system falls within a predetermined range.