I think it is 450, and yeah, thats not really enough to do much in terms of sharks. If your thinking of something really cool like a black tip (which one of my LFS's has and I cant imagine anyone being able to house them long term) you need a 20ft tank that is 10-15ft deep and about 6 feet tall, which maybe 2 people in the country do. So, get yourself a bamboo, 1, and be done with it. And next time somebody asks you what size tank you have, dont get snippy, and rude, just tell them so they can make an educated response to your question. Or did you already try this in the aggressive and FO forum and get chased out when you told them?