a chemical dispensing apparatus includes a housing that is connectable to a source of water , such as a standard garden hose , and an internal space in which is disposed a rotatable container containing a quantity of chemical concentrate to be mixed with the source of water as it flows through the housing and is dispensed from the housing from a sprinkler head or misting nozzle . the flow of water through the housing powers a water turbine which is connected to the rotatable container , such that the container is rotated as water flows through the housing . in an alternative embodiment , the water turbine is replaced with an electric motor . rotation of the container cause the chemical concentrate to dissolve which is then mixed with the water before it is dispensed through the sprinkler or mister .