Blastomussa not growing

Hey guys. I got a blasto about 2 months ago. Just has one head. It hasn't grown an inch since. It does fully open though so I assume it's happy. It's about halfway up the tank. T5ho lighting. 79 degrees. 430 calc. 1180 magnesium. 9.5 alk. It's kind of near a gorgonian. Maybe 5 inches away. Flow is probably low-medium. Vortex power head so it's not consistent. Any ideas?

Thanks