Okay... so originally I was going to start my 40gallon tank as a brackish water tank, but now I'm thinking of going in the opposite direction and go saltwater instead... okay so not so much opposite direction as furthur into the salty waters direction... Now, I'm curious to know what kind of fish should I put in the tank? I want some gobies of some sort, mabye a clownfish even, but do clownfish need coral to be happy? cuz I want a fish only tank........ ARGH!!! somebody please help me?! 
