Abstract: A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Membrane permeate passes through a bed of adsorption media optionally located in a tank with the membrane modules. The membranes are backwashed periodically with permeate, which bypasses the adsorption media as it returns to the membrane module.