I used to have a Spotted Scat in a 15 gallon aquarium, it started out in brackish and then i made it into full SW, the amazin thing is after 6 years it got to 8" in diameter (with fins extended), but had to give it to the LFS because we moved and couldnt take it. I have yet to see something more impressive then a 8" spotted scat (well except for a 8" tiger scat)