The species most often seen in tanks is Scarus quoyi, which is suitable for coral aquaria. It does have a large appetite, so the aquarium must have good filtration. 

Parrotfish are effective algae eaters for the reef, but some species will also live off rock corals. 
The Quoyi Parrotfish are regarded as reef safe. 

It is an advantage to have lots of algae in the aquarium which they can graze on as they eat often and constantly graze.