Oh yea deff don't want to risk losing fish and walls floor ect.
It doesn't look like much but there is a bulge
It does appear to be flexing a bit..A brace wouldn't help that though..it would just be supporting it in case it flexed more, but that doesn't mean anything since it's the glass on the outside, not the top. The brace that you're talking about is probably for the glass cover to support that. (correct me if I'm wrong)