Ok, I have a 150 gallon, 6foot tank and the top frame where the cross braces are has some cracking and is slightly split, most likely allowing a little extra bow. I should have fixed this a long time ago, but didn't. Now I am freaking out a bit and want to replace it. I have already acquired a replacement frame, just wonder if there was a way to swap this out while temporarily lowering the water level in the tank? I was hoping to leave like a 1/4 of the water in, with the live stock, swap it out and then refill. Any advice, especially from anyone who has done this would be greatly appreciated.