Abstract: A water filtration unit, comprising: a housing; a passive separator in the housing to receive a pressurized source of particulate-heavy water, to separate most of the particulate mass from the water and to output particulate-lean water; particulate egress means disposed at least partly within the housing to receive, and allow disposal of, the particulate separated from the water; at least one filtration module in the housing to each receive the particulate-lean water simultaneously, to filter remaining particulate and contaminants from the particulate-lean water by allowing passage of the water through porous filtration media of each module under gravity; and at least one outlet conduit coupled to an outlet in a wall of the housing to receive filtered water from the filtration modules and provide the filtered water to a fluid sink outside the housing.