A mixing system for a fluid tank is described herein, the system having a drive motor, an impeller capable of being submersed, a shroud having a sidewall enclosing the impeller, and a cutter mounted on the shroud and cooperating with a blade of the impeller to cut solids within the shroud. The shroud is open at both an inlet end and a discharge end for drawing in and discharging fluid from the tank. A recess is provided on the internal surface of the shroud, wherein the cutter is adjustably positioned within the recess. Additionally, the cutter is also detachable from the recess so that it may be replaced when worn. In use, homogeneity is maintained in a slurry contained within the tank by submerging an impeller into the slurry, the impeller being shrouded in a housing having an inlet opening and a discharge opening, securing a cutter on an internal surface of the housing such that during operation of the impeller the cutter cooperates with a blade of the impeller to cut solids within the slurry, drawing tank contents into the impeller at the inlet opening, cutting solid material in the drawn tank contents between the cutter and an impeller blade, and then discharging the drawn tank contents out the discharge opening back into the tank.