Congratulations on the Rohn 25. Ken McConnaughhay, KJ5BM, is doing the same thing. Craig told him a 4x4x4 concrete base should work. My 34' is wall bracketed, as you well know, has a 3x3x3 base (38 80# bags of concrete). I made mine 6" deeper, put in several bags of crushed rock and lined the bottom with HD plastic with holes for the cut off section that Roger gave me for a base.

By the way, I need you to come back and put the second rope pulley up and secure the new backup DX-EE coax to the tower. Bring your dad if he's still in town.