Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation equation governing those times scale has been presented in the present work. Macro and micromixing time represent two extreme mixing time scales, which governs the whole hydrodynamics characteristics of the surface aeration systems. By the help of experimental and numerical analysis, simulation equation governing those times scale has been presented in the present work.