A filter device having a vent device for inhibiting formation of a vacuum in the filter device. The filter device includes a drum for receiving the liquid wherein the drum includes a drum headspace. The filter device also includes filter sets for filtering the liquid. The drum is rotated to enable cleaning of filter media. The filter device also includes a frame having spaced apart supports for supporting each of the filter sets. A fluid passageway extends between the supports, wherein the fluid passageway provides fluid communication between the tank headspace and a filter set to vent a filter set.