An apparatus for making a solution, the apparatus comprises: (a) a hopper comprising: (i) a first side wall; (ii) a bottom; (iii) a top; (iv) at least one overflow weir; (v) a first liquid inlet positioned within the first side wall; and (vi) at least one nozzle assembly positioned inside the lower half of the hopper and coupled to the first liquid inlet, wherein the at least one nozzle assembly comprises a manifold having at least two nozzles (311, 312) spaced apart, wherein each nozzle (311, 312) has one or more nozzle outlets that are directed away from the bottom of the hopper and/or one or more nozzle outlets that are directed toward the bottom of the hopper; (b) a liquid holding tank positioned proximal to the hopper so that liquid in the overflow weir can flow into the liquid holding tank, wherein the liquid holding tank comprises: (i) at least one side wall; (ii) a bottom; and (iii) at least one liquid outlet positioned within the at least one side wall; and (c) a pump system physically coupled to the first liquid inlet positioned in the hopper and the at least one liquid outlet positioned in the liquid holding tank, wherein the pump system is configured to pump liquid from the liquid holding tank into the hopper; wherein the hopper further comprises a second side wall, a third side wall, and a fourth side wall, wherein the first side wall is opposite the fourth side wall and the first side wall is adjacent to and between the second side wall and the third side wall, characterized in that the hopper further comprises a second liquid inlet positioned within the second side wall and a third liquid inlet positioned within the third side wall, and that the second and third liquid inlets (115, 117) are physically coupled to a source of water via piping (124, 125) that is independent from the pump system. (a) a hopper comprising: (i) a first side wall; (ii) a bottom; (iii) a top; (iv) at least one overflow weir; (v) a first liquid inlet positioned within the first side wall; and (vi) at least one nozzle assembly positioned inside the lower half of the hopper and coupled to the first liquid inlet, wherein the at least one nozzle assembly comprises a manifold having at least two nozzles (311, 312) spaced apart, wherein each nozzle (311, 312) has one or more nozzle outlets that are directed away from the bottom of the hopper and/or one or more nozzle outlets that are directed toward the bottom of the hopper; (i) a first side wall; (ii) a bottom; (iii) a top; (iv) at least one overflow weir; (v) a first liquid inlet positioned within the first side wall; and (vi) at least one nozzle assembly positioned inside the lower half of the hopper and coupled to the first liquid inlet, wherein the at least one nozzle assembly comprises a manifold having at least two nozzles (311, 312) spaced apart, wherein each nozzle (311, 312) has one or more nozzle outlets that are directed away from the bottom of the hopper and/or one or more nozzle outlets that are directed toward the bottom of the hopper; (b) a liquid holding tank positioned proximal to the hopper so that liquid in the overflow weir can flow into the liquid holding tank, wherein the liquid holding tank comprises: (i) at least one side wall; (ii) a bottom; and (iii) at least one liquid outlet positioned within the at least one side wall; and (i) at least one side wall; (ii) a bottom; and (iii) at least one liquid outlet positioned within the at least one side wall; and (c) a pump system physically coupled to the first liquid inlet positioned in the hopper and the at least one liquid outlet positioned in the liquid holding tank, wherein the pump system is configured to pump liquid from the liquid holding tank into the hopper; wherein the hopper further comprises a second side wall, a third side wall, and a fourth side wall, wherein the first side wall is opposite the fourth side wall and the first side wall is adjacent to and between the second side wall and the third side wall, characterized in that the hopper further comprises a second liquid inlet positioned within the second side wall and a third liquid inlet positioned within the third side wall, and that the second and third liquid inlets (115, 117) are physically coupled to a source of water via piping (124, 125) that is independent from the pump system. wherein the hopper further comprises a second side wall, a third side wall, and a fourth side wall, wherein the first side wall is opposite the fourth side wall and the first side wall is adjacent to and between the second side wall and the third side wall, characterized in that the hopper further comprises a second liquid inlet positioned within the second side wall and a third liquid inlet positioned within the third side wall, and that the second and third liquid inlets (115, 117) are physically coupled to a source of water via piping (124, 125) that is independent from the pump system.