A shaker for separating solids from a drilling fluid includes a top screening deck(130), a flow-back pan(160) positioned beneath the top screening deck(130) for receiving an initially separated drilling fluid from the top screening deck. The flow-back pan (160) is divided into a plurality of channels (A, B, C, D). The shaker further includes a fluid distribution box (210), which includes a plurality of conduits (A, B, C, D). Each channel (A, B, C, D) of the flow-back pan (160) corresponds to one of the plurality of conduits (A, B, C, D) in the fluid distribution box (210) and each channel communicates a stream of the initially separated drilling fluid to the corresponding conduit. The shaker further includes a middle screening deck(140) and a bottom screening deck(150). Each conduit (A, B, C, D) routes the stream of initially separated drilling fluid to a corresponding one of the middle screening deck (140) and the bottom screening deck(150).