Provided are methods of inhibiting microbial fouling and improving efficiency in biocide dosing in an industrial process containing an aqueous liquid having a biocide demand. In exemplary embodiments, the methods comprise treating an aqueous liquid having a biocide demand with a biocide, monitoring the biocide demand of the aqueous liquid, and filtering a stream of the aqueous liquid. The filtering may be performed in a full-flow or side stream manner.