Dirty liquid enters the filter through the side inlet header, and is discharged into the dirty compartment. The dirty compartment is separated from the vacuum chamber located below by a filter media barrier through which clean liquid must pass while the solids are retained by the media. Solids accumulate on the media surface forming a filter "cake" which further improves filtrate clarity by removed by the media alone. To promote thicker "cake" formation, an increased pressure differential is created across the filter media by the clean supply pump which takes suction from the vacuum chamber. As the solids accumulate on the surface of the media, the vacuum created in the chamber below increases. When sufficient vacuum has been created, an indexing cycle is initiated in which the vacuum is released by a pneumatic vacuum break, allowing the liquid in the clean tank to be fed into the vacuum chamber during media indexing to insure uninterrupted flow to the work. The spent media and accumulated solids are removed by the automatic drag chain conveyor and discharged into a collection receptacle for disposal. When indexing is complete, the pneumatic vacuum break is closed and the clean tank is refilled from a side stream of the clean supply line with the excess liquid draining by gravity back to the dirty compartment