Abstract: A stacking portable water filter includes an upper and a lower canister, with the lower canister having a filter aperture which receives a filter cartridge therein. Untreated water received in the upper canister flows through the filter cartridge by gravity to be collected in the lower canister. Both canisters include an upper rim, with both upper rims having a substantially similar size and shape. A cover is also provided to fit on one or the other of the rims. In an operative positions with the containers stacked, the cover may mount to the upper rim of the upper canister. In a portable position with the upper canister removed from the lower canister, the cover may be mounted to the upper rim of the lower canister.