Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Here is the part that will take off and race across the tank, then it can blow apart. Or, it may crack slowly, and start seeping.
Either way, do not trust this tank.
If you want to set up a riparium and can turn this corner to the back then you could patch it. Silicon a patch of glass over it to stop the crack from running, but I still would not trust water above a corner that looks like that.