HELP plumbing a livewell

[jeremy5780]

Trying to get my livewell up and running but not sure how to plumb/setup. It is a round live well maybe 20-25 gallons there are three holes! one up near the top thata is 3/4 inch then one maybe five - six inches below the top hole that is also 3/4 inch and one at the very bottom that is closer to 1 1/4 inch I assume this one is the drain. I have a thru hull seacock with a clam shell for the water pick up. As well as two other thru hull seacock's. I have enclosed a picture to help understand!

[GT1000000]

Best guesses are attached...You can verify these by sticking a water hose to each one and have a helper see where they discharge at...

[BigLee324]

I agree with GT top is overflow, middle is fill and bottom is the drain