is the glass pane going to be the only peice of material on the veiwing side or is there going to be a lip supporting the sides of the glass also??
A lip will support all 4 sides of the glass.
I have some smaller angle that will support the side edges of the glass and the plywood sides. That will be bolted to the bottom frame and top frame. I did not want to run the welder in my living room. After looking at a lot of plywood aquariums that looked more like wood working projects than a tank build I realized that I could weld up a frame to hold everything together. The bottom frame is too heavy for one person to pick up by them selves. The top frame is about as heavy as I can lift by my self.
last idea lol...If you use .5 polypropolene or .5" plywood with more side supports you can gain some support from your angle frame top and bottom. I have .5 solid squarestock side supports every 7.5" around mind, 2.5" angle iron frame and the side walls bow out 1/4" in the middle wall. I used polypropolene to line mine but its rigidity should be pretty close to wood. There is aloooooot of pressure on that frame, may not be a terrible idea to add material and make it thicker to hold the wood more or just weld up another quick frame with 2.5"-3" angle.