I have a gold fish in my fw community tank with angels and a couple of severum. He has been in the tank for 2 years with the temperature around 78F, no problem.
I also have 5 silver dollars (1" in size) in my predator tank and I really like how they school. They also eat like little pigs, often grabbing the pieces of shrimp I feed my rays with and swimming about with it in their mouths.
