An underwater filtration system or operator which can be floated on and suspended in a river, lake, pond or other water body to filter water from the water body. The underwater filtration operator may be electrically charged with simultaneous introduction of continuous forced air to remove impurities from the water body and increase filtering efficiency and the system includes a split housing having a selected configuration and divided into one or more filtration units, each of which includes a filter medium or mediums for filtering water from the water body. A pump is provided in the interior of the system housing for receiving the filtered water from the filtration units and pumping the filtered water to a collection tank or dispenser, directly to an end user or to a reverse-osmosis water filtration unit for further filtration. This unique operator allows selected individual filtration compartments to be backwashed while other filtration compartments are producing filtered water without the necessity of an external clean water storage tank.