Disclosed herein are the methods of using specific di-cationic or multiple charged cationic compounds, which are derived from primary amine or polyamines through an aza-Michael addition with an α, β-unsaturated carbonyl compound or from polyamines through both an aza-Michael addition with an α, β-unsaturated carbonyl compound and a ring-opening reaction with an epoxide, in a fouling control composition to reduce microbial and/biofilm growth in a water system. The disclosed methods or compositions are found to be more effective than those methods or compositions including commonly used single quaternary compounds for reducing microbial or biofilm growth in water systems.