An inside-out liquid purification system comprising: a housing defining an interior space, the housing comprising: an inlet at a top side of the housing; a fitting at the top side of the housing and inboard of the inlet; and an outlet at a bottom side of the housing, the bottom side of the housing being conical in shape; a cartridge disposed within the interior space, the cartridge comprising: a top cap having an orifice and configured to interlock with the fitting to suspend the cartridge within the interior space; a bottom cap adjacent to and suspended above the bottom side of the housing; and a filter having an annular shape and extending between the top cap and the bottom cap, the filter defining a hollow vertical column aligned with the orifice such that liquid enters the cartridge vertically through the orifice and exits the cartridge radially through the filter, wherein the bottom cap of the cartridge is not in contact with the bottom side of the housing to form a void between the cartridge and the bottom side of the housing so that no upward extending features are present to prevent liquid from flowing out of the housing through the outlet in the bottom side of the housing. a housing defining an interior space, the housing comprising: an inlet at a top side of the housing; a fitting at the top side of the housing and inboard of the inlet; and an outlet at a bottom side of the housing, the bottom side of the housing being conical in shape; an inlet at a top side of the housing; a fitting at the top side of the housing and inboard of the inlet; and an outlet at a bottom side of the housing, the bottom side of the housing being conical in shape; a cartridge disposed within the interior space, the cartridge comprising: a top cap having an orifice and configured to interlock with the fitting to suspend the cartridge within the interior space; a bottom cap adjacent to and suspended above the bottom side of the housing; and a filter having an annular shape and extending between the top cap and the bottom cap, the filter defining a hollow vertical column aligned with the orifice such that liquid enters the cartridge vertically through the orifice and exits the cartridge radially through the filter, wherein the bottom cap of the cartridge is not in contact with the bottom side of the housing to form a void between the cartridge and the bottom side of the housing so that no upward extending features are present to prevent liquid from flowing out of the housing through the outlet in the bottom side of the housing. a top cap having an orifice and configured to interlock with the fitting to suspend the cartridge within the interior space; a bottom cap adjacent to and suspended above the bottom side of the housing; and a filter having an annular shape and extending between the top cap and the bottom cap, the filter defining a hollow vertical column aligned with the orifice such that liquid enters the cartridge vertically through the orifice and exits the cartridge radially through the filter, wherein the bottom cap of the cartridge is not in contact with the bottom side of the housing to form a void between the cartridge and the bottom side of the housing so that no upward extending features are present to prevent liquid from flowing out of the housing through the outlet in the bottom side of the housing.