a coalescer media flexible container for retaining coalescer media in the coalescer chamber of an oil - water separator is provided having a flexible enclosure and a randomly arranged , loosely packed coalescing medium . the flexible container has a top surface connected to a bottom surface . the flexible enclosure conforms to the shape of the coalescer chamber in which the flexible enclosure is placed . the flexible enclosure has an interior , with the flexible enclosure fabricated so as to permit liquids to easily pass into the interior of the flexible enclosure where the randomly arranged , loosely packed coalescing medium is retained . the flexible enclosure is preferably fabricated from a group of materials including plastic mesh , reinforced aerated plastic bags , wire mesh , fabric mesh , and netting . furthermore , in at least one embodiment of the invention , a planar sheetform member is located in the interior of the flexible enclosure directly adjacent the bottom surface . preferably each flexible enclosure includes a pair of retrieval means . a method of use is also disclosed .