Neither.

The livewells have a manual plug in the bottom. You can open it and drain them, or stick plug in and then fill them with the pump. Either.

IF you fill them and pull boat out of water, the water stays in livewell so long as you don't take out the plugs.

IF the livewell is full of water and the plug is IN, the water stays there. Turning on the pump switch does nothing but make the pump hum..........there's no outside water to pump in, so it doesn't pump any in, and it also doesn't pump any out. Period. The water goes out two ways only, A) through the drainhole with plug in bottom of each livewell, or B) being pumped out as new water is pumped in. If boat is out of water, it just hums (and probably burns up for all I know....I don't leave it on out of the water).

There is no recirculating valve. That is why I posted this, to ask how to get and install one, or something similar.