I have two saltwater tanks, a 37 gallon FOWLR with a clown, goby, puffer and a blenny and cherub angel in quarantine. I also have a 20 gallon reef with a yellow tail damsel. I want to add a royal gramma to the 37 gallon, but I am worried about the cherub angel being aggressive since the royal gramma would be added last. Which tank is the royal gramma best in?