An apparatus for mixing and activating polymer which includes the introduction of gas with water and polymer in order to create a variable density type foam which aids in the activation and enhances the efficiency of the polymer. The apparatus of the preferred embodiment provides the introduction of water and polymer into a mixing loop having a premixing manifold containing a static mixer, injecting or sparging gas into the outflow from the static mixer, blending and activating by mechanical agitation the water polymer and gas mixture, partially feeding back into the mixing loop the mixture to provide a desired level of polymer activation which is delivered at a desired rate of flow. This system provides capabilities for selecting the desired level of activation, levels of polymer concentration, levels of overall flow rate as well as controlling the various energy imparting elements of the apparatus.