A gravity-fed filtration apparatus includes a filter housing having a water inlet near an upper portion of the filter housing and a water outlet near a lower portion of the filter housing. A water filter having a plurality of discs is removably stacked within an interior cavity of the filter housing between the water inlet and the water outlet. An outer perimeter portion of each of the plurality of discs sealingly engages with an inner surface of the filter housing. A first disc of the plurality of discs comprises a first plurality of diffusers and a disinfectant media. A second disc of the plurality of discs comprises a mesh. The lower portion of the filter housing is configured to be disposed in the mouth of a water vessel.