It all depends on the setup that you want to have. Either you want a reef tank with corals and live rock, or you want a fish only tank, or you want an aggressive setup with maybe rays or sharks. In the beginning of my tank, I decided on fish only. I cycled the tank with 3 convict damsels, anbd then returned them and bough three false percs. They are good communinty fish, compatiple with all other non agressive fish, and are safe with corals nd inverts. Next I bought a yellow tang, which only is supposed to eat algae and vegetables. Although you can train them to reat meat and seafood. They are better alone or in big groups, but compatible and non agressive. Recently, I got a Coral Beauty, which is a drawf angel. Ive now decided to start buying some small corals, and these fish work fine with them. If you want to head in this direction, then you can buy fish similar to these. It all depends on what you want. I hope this helps a little. Reposnd if you have any quesions.