A big part of the reason I wanted a cube, was to accommodate the giant clam shell. I used to have a large koi pond, and had it displayed outside, by the pond. I left that hobby, and made this hobby bigger!! So, I had to choose a tank with no center brace, and room for this big, heavy thing. It is probably closer to 100lbs...really was tough to get in there and stabilize. When I took this shell, my mother in law offered me an even larger one they had. I must have been 150lbs!! It was too much trouble, and I took the smaller one. I am glad I did, the larger one probably would not have fit. I think she sold the other one to a different restaurant, when she retired. But, I was determined to make it a central point of my aquascaping.