...keen observation, yes I got 3 large discus (2 blue diamonds, 1 scribled Red), plus Electric Blues, Yellow Labs, dwarf blue zebras, 5 blood parrots, 5 large angels....tons, of corys, yoyo loaches, bristlenoses, leopard frog plecos, a few I can't remember. Guess what? due to their size (around 5-6" diameter), nobody messes with the discus!
The panel is solid glass...looks pretty thick, but can't tell just by knocking at it, it is embedded between fiberglass panels. Remember this tank is for aquaculture purposes...so it has to withstand some serious water pressure, tilapia, salmon, lobster banging & scratching...