Groupers don't get 600 pounds. That's one species. You're talking about the largest grouper in the world the Goliath grouper. I have a honeycomb grouper that doesn't get more then 12" long.
This one should only get to 12" as well. I researched before getting it. It's housed with the dogface puffer, lion fish, two spot wrasse, vlamingi tang, and Niger trigger.