An apparatus for separating solids from solids laden drilling fluid, the apparatus comprising a shale shaker and a screen assembly (300), the shale shaker comprising a base and a basket (30) isolated from said base, a flow tray (301) arranged in said basket (30) for directing screened drilling fluid, the screen assembly (300) comprising at least one layer of screening material (299), a screen support (340) having a perimeter with at least one support point within said perimeter, characterised in that the flow tray (301) comprises at least one raised portion (313a-313e) to support said screen assembly (300).