Abstract: A mixing system and valve(s) are provided for a tank or other container of liquid to be mixed. A directional flow control valve is secured within the tank. The directional flow control valve includes a plate secured adjacent an inlet supply opening or an outlet supply opening in the tank. The valve plate has openings for enabling controlled maximum liquid flow into or out of the inlet supply opening or the outlet supply opening, respectively. A floating disc is also provided within the valve and located in an aligned position to enable sealing engagement of the floating disc over the plate openings when the flow control valve is in a closed position, and to enable movement of the floating disc away from the plate openings when the flow control valve is in an open position. An inlet and outlet supply is also provided to supply liquid into and out of the tank. The directional flow control valve is secured adjacent either an inlet and/or outlet supply and the tank.