I am finally setting up a 225 gallon tank that I got last year sometime. The dimensions are 6 feet (length) by 2 feet (front to back) and 2 and a half feet (tall). The only problem that I am having is that there is no center brace across the top of the tank. the tank is used, I put all fresh silicon in, but I am still bothered by no center brace. What I am thinking about doing is setting up a center brace inside the tank using bricks (as in the stuff used to build houses). I'm wanting to make a center brace with them inside the tank and have it maybe upwards of 24" tall with a hollow spot in the top/middle for the fish to swim through a little easier. Also I'm wanting to use bricks as decor to kind of make it look like an old house or barn scene that was flooded out (maybe to build a lake?) long ago. My only concern at this point is, are bricks safe for fish? I know a little about how they are made, compacting rock, sand, dust, clay, etc. and then heating them into what becomes a brick. I'm just wondering if I do this will elements (mercury, iron, you get the idea) leach out into the water, making it poisonous for my fish? Also I am debating about not filling the tank completely up, maybe stopping somewhere between 18 and 24 inches high, leaving 6"-12" unfilled space at the top. If I do that I'm wanting to build ledges with waterfalls and things to create a really nice effect, and again bricks seem like the cheapest and easiest way to go.. If it's a matter that this will just make the water hard, not a problem. If this will poison the water and fish, then I've got a problem. What do you think?