US Patent 7329345 Dual dispenser

A cartridge holder and a floating dispenser system for dispensing materials into a fluid with the floating dispenser system including a cartridge holder with receptacles for removably attaching or detaching at least two cartridge dispensers therein to allow one to simultaneously dispense materials into a fluid system by placing the floating dispensing system in a body of fluids and to replenish the system by merely removing and replacing a cartridge in the holder.