Gravity fed livewells

Okay, I just bought this boat that has one of these. How well do they work? I guess I'm gonna have to run an aerator to it. During the course of a day, does that water replentish itself during travel on water? It's a decent size. Can hold a good amount of minnows, maybe a lunker. Here's a pic. https://www.geocities.com/mallyrotten/livewell_dollar_bill.JPG

By gravity fed, do you mean that there is no pump at all?

I would think that the livewell would drain itself while on plane unless you put a plug in it if that is the case.

That is what iam planning to do with mine. By "gravity fed" you mean the tube for a drain right? The tube will keep the water up at the level of the top of the tube. You will need to drill another hole in the livewell (in the corner), put a thru-hull fitting in, run it to a aerator, and run that to a spray bar. That will pump the freshwater in, and as soon as it gets to the level of the tube, it will run out and drain. Hope tha makes sense.