<p>A filter cassette having opposing rectangular side panels with at least one pair of filter media containers there between wherein each filter media container has a pair of opposing rectangular end plates and a pair of opposing rectangular media screens, each pair of containers are in a "V" configuration with adjacent end plates having a unitary configuration and at least one media fill aperture for each media container on a non-sealing side of the filter cassette, outermost end plates on a sealing side of the filter cassettes extend between corners of opposing side panels forming a substantially smooth sealing surface, and a fill cap is attached to each unitary pair of end plates having media fill apertures enclosing the media fill apertures.</p>