Yes our tank all look the same... somehow
Don't think your tank is suitable for Black Tip Shark as it is too narrow, not enough space for the shark to turn its body... they have to continuous swimming or they will sink
Perhaps you wanna try acquire exquisite specimens such as Black Tang (or even Gem Tang) lor There's a reefer in Reef Central spent US$18000 on 12 Gem Tangs That kinda thing... or perhaps you can mix a bit of corals in your tank to set yours apart from the normal FOWLR setup.
All the best in discovering yourself