Bottom glass cracked

[FSM]

Major manufacturers typically use tempered glass for the bottom of aquariums... It makes sense to me to do what they do... Although since yours is cracked, not shattered, obviously it isn't tempered...
What I would consider is...

Remove the bottom trim... silicone a new piece of glass (I suggest .5" tempered) to the outside of the bottom of the tank that is the full size of the bottom surface of the tank...

I would also silicone the crack closed to prevent water from seeping in and "rotting"...

I would also be sure to support the full bottom of the tank as opposed to just bracing the perimeter like glass tanks usually are.

Why not just replace the whole bottom panel?

 

[Poklei]

shuld just resell it on craigslist its garbage some idiot will buy it for cheap

 

[Toby_H]

Why not just replace the whole bottom panel?

It's a lot more work...

I wouldn't feel comfortable removing & replacing the bottom pane of glass without completely dismantling the whole tank and resiliconing every piece back together... and doing that with such a large tank and keeping everything flush and square is quite difficult.

Cutting the borken bottom off and leaving the verticle joints as is would mean in places you are asking new silicone to stick to old / cured silicone... This rarely makes a true water tight seal...

Adding the new glass over (actually under) does make the tank heavier, which is a pain... and changes a bit about the stand, which is insignificant in my eyes...