An apparatus for the treatment of drinking water contained in a vessel is disclosed. The apparatus comprises a housing, a drinking water inlet and a drinking water outlet. The apparatus also includes a pump operable to pump drinking water from the water inlet to the water outlet, wherein the water outlet and pump are configured to dispense drinking water generally upwards from the water outlet below a surface of the drinking water to cause a continuing disturbance in a surface of the drinking water contained in the vessel. In one example, the apparatus is used to reduce algae in the water. In another example, the apparatus is used to increase the oxygen content in the water.