Brad all you have to do is plug the livewell and fill it up all the way. When you want to add fresh water to the livewell just turn it back on, there should be an overflow at the top of your livewell that flows back into the lake. In other words you could leave your livewell pump running at all times and it wont (if there is a overflow) fill up into the boat. This works really good and the fish will stay very active.