Now that you are here, what size tank do you plan on putting them in? If you didnt know before, both of these species require rather large tanks that are bigger than most of our abilities to have. Novice had one about the right size and even though it was big enough for him to swim in it, I think a full sized black tip would still have swimming issues even though it should physically fit ok although they do get 8 feet long. Might just be my lack of scale perception though. Not sure on the size of whitetips. I do know they are open water swimmers like blacktips and thus need alot more space than your the "aquarium sharks group"(if there is such a thing).