Abstract: A method for clarifying coke quenching water or other waters which are contaminated by solids, with a wide grain spectrum, in an operation in which the fine portions of the solids suspended and carried along with the water are removed from the water by filtration and the clarified water is returned in a cycle, comprising, depositing the water into a filter shaft so that the substances removed from the contaminated water build up in the shaft and themselves form a filter bed, continuing to pass the water through the filter bed from the top to the bottom in a manner so that the velocity of flow of the water in the filter bed decreases constantly and so as to preclarify the water which passes through the bed and subsequently refiltering the preclarified water in a trough basin which rises from the bottom to the top. Thereafter, the refiltered water is directed into a discharge channel from the trough basin which overflows above the basin.