I have a couple of feather dusters in my crushed coral. I just took my finger, made a very shallow trench, placed the tube body in it, covered it over, and VIOLA !!! They are very happy. They are filter feeders and do not require a lot of attention. I have oter corals and I use ZOE and strontium, and the feather dusters are loving it. I would also mention that they should be in at least a medium water flow.
Good Luck