Abstract: A diluent such as water is sprayed from a nozzle through a screen onto water soluble packages of chemical supported on the screen to produce a solution for treatment of a system. The solution falls into a reservoir and is recirculated through the nozzle onto the screen for a duration sufficient to dissolve a load of chemical into solution. The concentrated solution is dispensed to a system. The reservoir can be flushed into the system before recirculating solution to the nozzle for further chemical dissolving. Chemical-containing packages can be loaded at any time without system interruption. Chemical is supplied in powder or solid form.