Method and apparatus for filtering a liquid

A filter for filtering a liquid by causing the same to flow upwardly through a particulate filter media, comprising a main tank having a central axis, at least two upstanding sub-recipients integrated within said main tank for containing a particulate filter media adapted to filter a liquid seeping therethrough, inlet means for delivering and distributing the liquid to be treated into said sub-recipients, outlet means disposed above a top surface of said sub-recipients for discharging the liquid from said main tank as a filtrated liquid, a transport device comprising at least two transport conduits extending substantially centrally into respective ones of said at least two sub-recipients for directing dirty filter media into a central washing device adapted to wash the dirty filter media as the same passes downwardly therethrough in counter-current with a wash liquid flowing in an upward direction within said washing device, and at least two filter media return pipes extending downwardly at a depending angle from a bottom end of said central washing device for returning cleaned filter media into respective ones of said at least two sub-recipients.