A floating media filter comprising: a. a filter housing having an influent inlet and an effluent outlet; b. a floating media positioned in the housing for forming a media bed when the filter is in a filtration stage, the media bed having a lower surface; c. a diffuser trough extending at least a part of the width of the filter housing, the diffuser trough including an upper edge, the diffuser trough: (i) positioned in the filter housing such that the lower surface of the media bed, when the filter is in the filtration stage, is below the upper edge of the diffuser trough; and (ii) having a shape which directs influent in a predominantly upward direction into the media bed, wherein the influent inlet directs influent flow in a path substantially along an interior length of the diffuser trough; and d. a backwashing mechanism, which during a backwashing stage, causes dispersion of the media bed, and the backwashing mechanism is at least one from the group consisting of: (i) a charge chamber selectively discharging air into the media bed while allowing liquid to enter the charge chamber; (ii) a constricted throat in the filter housing below the media bed and a valve allowing discharge of sufficient liquid to cause a rapid drop of the media bed into the throat; (iii) at least one propeller positioned in the filter housing and rotated with sufficient speed to disperse the media bed; and (iv) at least one paddle positioned in the filter housing and rotated with sufficient speed to stir the media bed. a. a filter housing having an influent inlet and an effluent outlet; b. a floating media positioned in the housing for forming a media bed when the filter is in a filtration stage, the media bed having a lower surface; c. a diffuser trough extending at least a part of the width of the filter housing, the diffuser trough including an upper edge, the diffuser trough: (i) positioned in the filter housing such that the lower surface of the media bed, when the filter is in the filtration stage, is below the upper edge of the diffuser trough; and (ii) having a shape which directs influent in a predominantly upward direction into the media bed, wherein the influent inlet directs influent flow in a path substantially along an interior length of the diffuser trough; and (i) positioned in the filter housing such that the lower surface of the media bed, when the filter is in the filtration stage, is below the upper edge of the diffuser trough; and (ii) having a shape which directs influent in a predominantly upward direction into the media bed, wherein the influent inlet directs influent flow in a path substantially along an interior length of the diffuser trough; and d. a backwashing mechanism, which during a backwashing stage, causes dispersion of the media bed, and the backwashing mechanism is at least one from the group consisting of: (i) a charge chamber selectively discharging air into the media bed while allowing liquid to enter the charge chamber; (ii) a constricted throat in the filter housing below the media bed and a valve allowing discharge of sufficient liquid to cause a rapid drop of the media bed into the throat; (iii) at least one propeller positioned in the filter housing and rotated with sufficient speed to disperse the media bed; and (iv) at least one paddle positioned in the filter housing and rotated with sufficient speed to stir the media bed. (i) a charge chamber selectively discharging air into the media bed while allowing liquid to enter the charge chamber; (ii) a constricted throat in the filter housing below the media bed and a valve allowing discharge of sufficient liquid to cause a rapid drop of the media bed into the throat; (iii) at least one propeller positioned in the filter housing and rotated with sufficient speed to disperse the media bed; and (iv) at least one paddle positioned in the filter housing and rotated with sufficient speed to stir the media bed.