Control the Flow
As you pump water into a circulating livewell, old water exits from a screen drain near the top. To avoid an overflow, the drain hose needs to be about twice the diameter of the inbound hose. So if you have a 1-inch-inside-diameter feed hose, for example, you need a 2-inch-ID drain hose. Control the flow by adjusting the valve on the outbound side of the pump. Measure flow by timing how long it takes to fill; for up to 32 gallons, a six- to eight-minute fill time is good; for tanks over 32 gallons, shoot for eight to 12 minutes.