YSI 6850 [606850] Flow Cell. Installation of the YSI 6850 flow cell is easy. Simply thread the flow cell on to the probe module of the Quatro cable assembly. Once secure, water can be pumped to the flow cell with a user-supplied pump. Water enters through the bottom of the flow cell, and passes through a diffuser plate. The water will leave through an opening at the top of the cell. This design ensures that flow is distributed evenly through the cell, eliminating dead zones of no flow along the sides.