i have a 210 gal with two 400w halides on it, in the center i do have a very large brace that is about 10 inches wide. The brace does cast a shadow but not that much of one to where i still cant put some softies. I just stacked the rocks on both ends of the tank under the lights and have the middle of the tank as open waters. In fact i love my tank this way because it gives your fish alot of swimming room and its a blast to drop some algae sheets in the middle to get the fish out in plain view. You could add a third light in the middle to evenly distribute the light but the real question is, do you want to add another 400w of halide lighting to your tank. The two lights alone in my area sucks up about 50 bucks a month in pg&e. Just a thought though