Ok ive had these before and ive always put them in like a hole in the LR. But I dont have any more holes is the LR. is it ok to like wedge a feather duster in between 2 rocks? Where else can i put it?
anywhere there is good current. i've seen them stabbed in the sandbed, stuck in holes of rocks (as you mentioned), and even banded to rocks. whichever paints your "portrait", make it happen. they are filter feeders and do not recommend a specific amount of light.
HTH and KEEP REEFING!
Feather dusters aren't too particular where you place them. As long as the spot is stable, so the doesnt move too muh or if it can fall. You can even stick it in the sand. The main thing is that it gets adequate current so it can trap its food.
Do you know the specie of feather duster?
Generally the large fragile feathery dusters are found naturally in the sand in mild to moderate current and the tightly coiled firm dusters are found in rock in high to extreme current.