Abstract: A filter cartridge for use in gravity-fed water treatment systems wherein filter elements include a dome-shaped hydrophilic porous particulate carbon powder block filter in a polymeric binder. The filter has a closed upper end and an open lower end with sidewalls extending there between, additional filter media and includes ion exchange resins and a fine mesh hydrophilic filter sheet to reduce contaminant content of water for drinking purposes.

Abstract: A multi-stage water purification device includes an untreated water compartment having an untreated water inlet and a treated water compartment formed from a resilient material. The compartments are segregated from one another. An outlet is in flow communication with the treated water compartment. A first unidirectional valve is disposed between the treated water compartment and the outlet and is configure to permit flow out of the treated water compartment only. A filter is disposed between the untreated water compartment and the treated water compartment. The untreated water flows through the filter to produce treated water. A second unidirectional flow valve is positioned at the discharge of the filter and is configured to permit flow out of the filter and into the treated water compartment only. Water is introduced into the untreated water compartment and the treated water compartment is deformed to reduce the volume therein.