Tank is thrown away lol. Just a surprise to see that as I never would even think of this.If its center bracing you should check the tank for bowing.
If it stresses the tank to much it could crack.
I would try to install something to support the center of the tank.
A temporary quick fix would be a bar clamp if you happen to have one.



BTW, I'm with backfromthedead, I'd help you get rid of it, and put it to use for the next 10 years, if not as a tank, as a sump.Where uh, did you throw it away?