That is a good point but a BB is so much easier to clean than a sand bottom tank, its one of the main reasons I like itI like the look of sand. I hate the look of dirty sand. I did a trial temporarily when I was waiting to put up my new tank and was BB on my old tank. It still got pretty dirty if you didn't keep it clean like sand. So that said I would rather work to keep sand clean than a barebottom.