The present invention discloses a water filter, used in the purification of mains water supply which comprises a vertically placed filter vessel (4) with a filter media (13), a system of valves (A to G), an inlet (61), an outlet (31), a backwashing port (51) and an effluent outlet (121). A fenestrated sheet (11) is disposed at the common adjoining end between a bottom compartment and the filter vessel (4); and the filter media (13) is placed inside the filter vessel (4) above the fenestrated sheet (11), leaving the top portion of the filter vessel (4) unfilled. The bottom compartment is provided with a base opening (8) which leads to a bottom sedimentation chamber (9) or alternatively is elongated and functions as a sedimentation chamber (9) on its own right. The system of valves (A to G) is selectively manipulated to invoke a water purification operation, or a backwashing operation, or a rinse operation, or a bypass operation. During water purification operation mode, mains water moves upwardly in an anti-gravity direction through the filter vessel (4), where the filtered water can be inspected visually through two transparent viewing ports (2) installed opposite each other towards the top portion of the filter vessel (4). A backwash operation mode is performed in the reverse direction, through a backwash pipe (5) embedded within the distance of the filter media (13), substantially at the middle of the filter media (13). The backwash pipe (5) allows the removal of coarse contaminants using mains water whereas finer contaminants are removed by the filtered water at the top of the filter vessel (4). A rinse operation mode is also taught.