I'm starting my 200gal build and starting with the sump first. I will show you how I do it.
The sump is about a 79gal measures 49 3/4"L x 24"W x 16"H. I used oversize sheet of 3/8" Plex "G" which is 50"x99", great for those who have to have a 24" deep tank (inside dimensions)
On with the build.
The plans, gotta have a map of what you want, where it's gonna go and if it'll fit or not.
I didn't take any pix's of the cutting as I have my wholesaler do that. But the routing is the next step
My router table, I have a total of 3 leafs if i need the room for those longer tanks
The working end
What's left after routing, a big mess that sticks to everything. Too bad I can't melt this and make a sheet of plastic
The ends pieces
The baffles
The front and back and top and bottom pieces
The filter Sock Holder
The tools: