Sump Plumbing and Set Up

[LilBabyFox]

I got a REALLY good deal on a 65gallon tank with a sump and a BUNCH of extra reef equipment. I've been looking into how to set up the plumbing and sump itself, but I'm lost. There is a back center overflow with 3 holes for plumbing. Hubby took some pics of the plumbing beforehand, but the staging is throwing me off with the sump since it doesn't match diagrams Ive seen. Any ideas of the sump staging? There was also egg crate in the sump as well. I included limited pics of what was there before tear down vs right now.

 

[csnmusic02]

it looking pretty self explanatory the 2 bigger pipes are the drains that flow into the first chamber and the last pipe well center is your return pipe from pump back to tank

 

[csnmusic02]

so drain pipes go into first chamber and the water rolls over to filter socks into the chamber where protein skimmer goes and the last chamber is where your return pump goes and they way with it had the valve that your main siphon for drain and the other was your back up drain

 

[LilBabyFox]

so drain pipes go into first chamber and the water rolls over to filter socks into the chamber where protein skimmer goes and the last chamber is where your return pump goes and they way with it had the valve that your main siphon for drain and the other was your back up drain

I guess what confusing me is why theres just a baffle instead of the typical bubble wall. Thought that the egg crate I saw was related but he may have just thrown it in there when he tore down the tank