I've had a Scopas tang in my reef tank for about 6 months now. He's kind of shy but doesn't take to new additions all that well. He's harassed a couple of new fish for a few days, but nothing terrible.
Like all tangs, they need their sea veggies. I feed mine Seaweed Selects at times, but he likes the Nori (sushi) dried seaweed sheets the best. He also eats frozen brine, mysis and Spirulina enriched brine shrimp and sometimes flake food.
He's a very active fish and needs lots of room to roam. I have mine in a 75g reef, but as he gets bigger I will have to upgrade the to a bigger tank.