Mine recently lost it's feather. I found it in the plate corals mouth. This was about a week ago. My wife noticed last night that a new feather is starting to poke out of the hole. When I first got mine I just laid it on the sand and it moved to just beneath a rock. It likes this spot.
I use cyclopeze and it only gets what food is in the water column.
If your calcium, alkalinity, magnesium are at the approriate levels the critter should be all right. Granted that the rest of the parameters are ok as well.
Regards,
Pat