A method, apparatus and system for flowing a fluid from an inlet flush nozzle onto tiered plates in a trough is provided. Material may fall from a deck in a vibratory separator, such as a shale shaker, into the trough, which is attached to the separator. The trough has a main inlet and the inlet flush nozzle that opens to tiered plates. An external pipe may feed the fluid into the main inlet and the inlet flush nozzle to lubricate the tiered plates in the trough. Material falling from the vibratory separator may float on the fluid to flow toward an outlet of the trough. A single plate with perforations may be used instead of the tiered plates to permit the fluid to penetrate the perforations to suspend the material, allowing the material to flow across the single plate to an outlet.