This is the actual real Garf Bonsai that we've been growing for a longtime (15 years +).  It's a show piece in the Acropora species.  This Acropora will acutally let you know if your Alkalinity is too high.  It prefers Alkalinity below 8.5dkh.  It will get more purple if under 8dkh.
 
Requirements
Lighting: High  about 300+ par
Flow:  Medium / High
Cal 400-440, Alkalinity between 7.5-8 Dkh, Mg 1400