I built a stand for my 180g. Stand looks great but... I used a level at each stage during the build but the top is bowed in the center. After several deadening attempts to fix/ repair, I am at a lost. I've put far too much time, effort and money into this project to start over. The top is 3/4" Baltic birch plywood. When I lay my 6ft level on it, there's a noticable "frowny face"


