An apparatus for forming a water solution of a chemical from a solid chemical, the apparatus comprising: (i) a housing, having a top, a side, and a bottom, where the top and the bottom are connected to one another by the side, said top, said side and said bottom form an interior compartment, and the housing having an upper portion and a lower portion; (ii) an inlet located in the lower portion of the housing, the inlet allowing water to be contacted with the solid chemical to enter the housing; (iii) an outlet located in the upper portion of the housing, the outlet allowing the water contacted with the solid chemical to exit the housing; (iv) a nozzle disposed within the interior compartment, said nozzle is connected to the water inlet and said nozzle being located within the interior compartment of the housing in the lower portion of the housing, wherein the nozzle allows water entering the housing through the inlet to contact the solid chemical; and (v) at least one support located within the interior compartment positioned between the nozzle and the top of the housing, said support being adapted to receive and position a cartridge containing the solid chemical within the interior compartment of the housing; wherein the top of the housing comprises an opening which allows a cartridge containing the solid chemical to be inserted into the housing, and the apparatus further comprises a cap, said cap being adapted to cover the opening of the housing and to form a water tight connection with the top of the housing; the apparatus characterized in that the apparatus further comprises a removable cartridge containing the solid chemical, said cartridge having a first end, a second end, and a sidewall connecting the first end to the second end, wherein the first end, second end and sidewall form an internal chamber, said internal chamber containing the solid chemical, and the cartridge being adapted to fit into the interior compartment of the housing between the top of the housing and the nozzle, wherein the cartridge contacts the at least one support located in the interior compartment of the housing and the at least one support positions the cartridge containing the solid chemical within the interior compartment of the housing, and such that the cartridge may be inserted into the interior compartment through said opening in the housing; and wherein the first end of the cartridge comprises a porous grid, and when the cartridge is positioned in the interior compartment of the housing, the cartridge being inserted in the housing such that the first end is positioned near the nozzle and the second end is positioned near the top of the housing. (i) a housing, having a top, a side, and a bottom, where the top and the bottom are connected to one another by the side, said top, said side and said bottom form an interior compartment, and the housing having an upper portion and a lower portion; (ii) an inlet located in the lower portion of the housing, the inlet allowing water to be contacted with the solid chemical to enter the housing; (iii) an outlet located in the upper portion of the housing, the outlet allowing the water contacted with the solid chemical to exit the housing; (iv) a nozzle disposed within the interior compartment, said nozzle is connected to the water inlet and said nozzle being located within the interior compartment of the housing in the lower portion of the housing, wherein the nozzle allows water entering the housing through the inlet to contact the solid chemical; and (v) at least one support located within the interior compartment positioned between the nozzle and the top of the housing, said support being adapted to receive and position a cartridge containing the solid chemical within the interior compartment of the housing;