A method of filtering a fluid with components includes providing an alternating pressure. The alternating pressure yields an oscillating transmembrane pressure through volume and pressure variations within a filtration chamber while sealing the filtration chamber. A separation surface can be housed in the filtration chamber wherein an influent is introduced. Components can be concentrated on the separation surface, effectively removing some or all of them from the fluid. To flush the filtration chamber and separation surface, a backwash fluid and components can be introduced and removed from the filtration chamber. While both the components are being concentrated and backwashed, the system can maintain the oscillating transmembrane pressure and varying volume and pressure relative to the separation surface.