I took a 2x2" square piece of acrylic and used Weldon 4 and adhered the 2x2 square to the main base piece. Once adhered together that gave me about a 1/2' of dept, and I drilled almost all the way thru the 1/2" and applied more Weldon when placing the rod in the dept to cure before sliding the drilled rock thru to the base. Hope that helps..
Found out the hard way that the sump did not fit in between the door opening of the tank stand.
When in Rome do as the Romans do. Drop it in.
Had to slide the 210g off to the side and then remove the center piece of wood to drop it in them replaced the brace.