great build. I have the same tank with the stock stand and sump. I am so glad that I stumbled upon this build as the stock stand is starting to fail and II want to go with a metal stand. Your detailed description of how you built it came in handy as I had something to give to the fabricator. How is the apex panel attached?
The apex and other controller pieces are all screwed to a 1/4" thick panel of marine starboard (HDPE).
The panel is screwed to some 1/2" square stock steel, which is welded to the stand