Acropora is the species most hobbyists wish to attain to, and with enough experience, time and money, they will eventually have them in their reef.  A decade ago you could purchase a small colony and put it in your tank. Of course frags existed back then as well, and we grew ours out from frags because it was fun to observe and usually cheaper. They grow in different ways, some like a bush, others like a table, and others extending branches. Here are three that grew in my reef.