I myself wouldn't trust a tank built with a center brace that had it removed. It might not break right away or ever but the glass will be under a constant stress load and bumping it or hitting it just right might put it over the edge. Time for some risk assessment!
Having said that, my 135G. blew its center brace and I made two replacements for it out of 1" x 1/8" steel flat bar. I'm pretty happy now because my T-5's can sit about 1 1/2" off the surface.
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universal health