Generally considered very difficult, in my understanding, because the amount of food would compromise water quality.
Can you post a picture of your Xmas tree rock and worms - they are very different.
I have one yellow-beige with fine polyps and may be 1/2" (1 cm) high colorful crowns - there are fed by fine food, that will fit the mouth, pulverized seafood (what is left from thawing fish food - frozen cubes of mysis, marine cuisine, shrimp, fish) with addition of the dry fine food, a pinch of ZoPlan, I had read somewhere, that it is in 10-250 micron range. If you can order Golden pearls of small sizes, or anything withing the smallest range (not Marine Snow, Kent ZooPlex, ChromaPlex or Microvert - the last 3 I tried, prefer the dry food). Phytoplankton may be added too - I'm not adding it, but have microalgae, growing on the glass.
Another of my Xmas tree rocks is brown, large polyped, with larger crowns, may be 3/4" high. Same food for this, plus the bigger zooplankton - frozen baby brine shrimp, dried cyclop eeze. Hard to say, who eats this food - there are sea stars, vermetid worms, feather dusters and bivalve mollusks on these rocks too, but food is disappearing withing half of hour. Try at least two big meals (without filtration in this time) in a day for them.
The light is preferably bright, nitrates and phosphates - low, the flow - relatively high, but without bending the crowns.
Two more things - watch for bristle worms, they may occupy the holes in the rock, replacing the more interesting organisms, and they have a very good vision - will close every time, when somebody passes the tank. Try to orient them so, that it happens more rarely.
Post pictures and progress of your Christmas tree rock and worms, will you?
Some links:
Toonen's article,
thread on feeding and care,
another article,
another thread,
one more thread.
