I am wondering what peoples opinions are of rays in a 210g display. I am new to aggressive tanks but I am not new to saltwater aquariums. I have owned reef aquariums for the last 8 years or so with success. I have been thinking about building my 210g into "species" stingray tank. The dimensions are 6 x 2 x 2.5. There would be minimal rock work in the tank and perhaps a few other unique tank mates. I am in the "thinking" stages as I am just starting my research in to "other than reef" aquariums. can rays be successfully kept in a 210?