Questions - Need some input

Ok everyone this is my first post. My name is Larry and I am setting up a 150g mixed reef tank. I have decided to DIY some of the if the things I need for the tank, ie the stand, canopy and sump. I have already started on the stand, I am building a steel frame stand covered in wood. I am waiting for quotes on getting it powder coated, and while I wait I want to get started on the sump. I am using a 40g breeder with the dims of 36 x 18 x 16 as my sump and using a ASM G3 skimmer which has a footprint ...