Hello I am completely new to the Saltwater tanks.... I have two fresh water tanks (55 gal and a 29 gal) and one empty 20 gal long tank. I was wondering if i should start out with getting my toes wet in one of those tanks or just go all in on brand new tanks. I am also wondering if there is any combination of coral, fish, invertebrates that i could put together to make the tank as self-sufficient as possible. Any and all information would be greatly accepted.