flyyyguy: Can you post a little more information?
Tank and Christmas tree rock photos, in short setup, tank feeding, filtration, when you started to keep it, when worms started to reproduce, old and new worms photos.
Especially water - is it artificial salt mix or oceanic water, salinity, temperature, alkalinity, location of the worms relatively to the flow.
Is skimming and filtration off for a some time during the day, by any chance? You see, I have the sun coral spawning, but not the Spirobranchus worms...
I'm no way demanding proof (really hate this), but making this information available to all of us, you will help many other, so far less successful keepers.
Will really appreciate this.
BTW, I bought green pavona with few Spirobranchus worms, and one - on the hairy mushroom rock.