as I'm doing the final prep and wiping down the inside joints with acetone, I hear three loud pops which turn out to be the top plastic frame splitting in three places. Two didn't separate so much and one did, although all three were all the way through.

This was the larger one. Tank is upside down on the stand.

So, just to be absurd I'll it possible to run a 125 gal tank with this type of damage, or does this cracked top frame necessarily need to be replaced? All three breaks were in the middle of the longer sections of the frame and none were too close to a cross support.

Top view...

I've been told my tank is an Aqueon brand. The glass measures exactly 18" x 72" and the top and bottom frames are two inches tall.

If it's at all possible to replace the top frame then I might as well do both. Anyone know where I should look to purchase these frame parts? Thanks.