A method of producing stable disinfectant for use as a biocidal composition. The method comprises: providing reagents, asynchronously feeding the reagents into a wide space, and allowing all the reagents to come into contact and mix with each other. The reagents comprise: a) an amine source in concentrated form, b) an oxidizing halogen compound in concentrated form, and c) a diluent. The use of asynchronous feeding and a wide space results in a dynamic biocide regimen. This regimen results in a changing environment that infestations have difficulty adapting to. This method also imparts superior results due to the avoidance of channeling effects which would otherwise weaken the effects of the biocide.