How do you fill the livewell? 

i own a 96' 367 and it has aerator toggle switches for both livewells, fore and aft. they're located on the switch panel along with the lights and accessorie switches, just forward of the throttle.

I have a 99 Renegade 20 and it has switches on the console for the pumps and lever next to the flood by the drivers seat to select if you want to fill, drain etc. 

So close and turn aerator to fish?

If I use mine, that's what I do.   I use mine for storage more than anything, seldom ever put water in it.   My bass fishing is mostly C&R.  I've always said, what few bass I eat, probably cost me about $5,000 per pound.