Agree! Thermopane windows are rather fragile out of the frame. <I broke one last year with just a slight bump.> All the strength is in the frame, and the glass is only 1/8". That is waay too thin for any tank.
For a big tank like yours, you might want to consider acrylics. 1" thick acrylics (what I would suggest for a 4' tall tank) would weigh much less than glass. It is much more expensive tho.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.