Abstract: A depth filter comprises a filter column having opposed inlet and outlet ends containing particulate material. The particulate material is selected in such a manner to provide a lightweight filter which retains equivalent high performance to heavier filters.

Abstract: A system is provided for removing iron and/or other chemically reducing substances from potable water having a pH between 5 and 9. The system includes a tank for receiving the water which tank contains a bed of activated carbon. The untreated water is aerated prior to its communication with the activated carbon. All of the aerated water is allowed to flow through the bed and the activated carbon provides a catalytic action, whereby substantially all of the oxidation occurs throughout the bed of activated carbon and the use of chamical oxidizing agents is obviated. The tank provides a reaction site for oxidation in the catalyst, precipitation of the oxidized ions, and retention by filtration of the precipitated particles.