Flow-Rite MV-02-FN01 V2F Control Valve Allows a single pump to perform the basic livewell functions necessary to keep your catch alive in a passive or automatic manner When the first fish is caught, place the valve in the "AUTO" position and turn on the pump When the boat is off plane the pump will recirculate and aerate the Livewell water and simultaneously blend in a portion of fresh lake water When the boat is put on plane, the valves check flapper will prevent water loss out the drain, and allow the pump to continue its recirculation duties