yea write down what you want to stock and envision it in your mind then you will know which route to go, such as fish only or whatever. It is cheaper to start off with a fish only, but will cost you more in the long run for upgrades to coral, such as lighting, etc. Bigger the tank, the better as you have more water volume to work with and will see your levels going off the chart before it happens and can take appropriate action. The bigger the tank, the more its gonna cost u to get started and maintain.. Alot of variables in this hobby that I have found so far..