Do you have any experience with Freshwater? Or Saltwater? Most Freshwater concepts carry over to SW, but there are added factors you don't have to deal with in FW. SW is more fussy.
I have some large tanks, and I have SW, but I don't have have a large SW tank, for two reasons - money and hassle. With big fish in big tanks, one of the keys to success if regular, large water changes. While in SW you typically don't do the really large changes like FW, if still becomes quite and expense and hassle to do wc on a big SW tank. In addition everything is more expensive, though there are ways to do SW more cheaply than I once thought. If money isn't an issue it is much more doable, because not only does the expense not matter, but you can buy fancy gadgets that will make your life easier.