Abstract: Chemicals for a sprayer tank, particularly in dry dissolvable form, are mixed with water in a separate mixing container prior to adding to water in the sprayer tank. The mixing container has a hopper bottom with a perforated discharge control at the bottom apex for controlling the exit of mixed chemicals and water. An injection elbow is mounted on the hopper bottom for directing return water downwardly toward the apex for agitation of dry dissolvable chemicals collecting at the apex. Two valves are provided mounted on a common frame supporting the tank. The valves can be operated to control recirculation of water and dissolved chemicals back into the mixing tank and can be operated so that the same pump is used for filling the sprayer tank from a supply tank and for filling the mixing tank with mixing water for the chemicals.