Shrinking Feather Duster?

[briterco]

I have 3 feather dusters, located in close proximity in the tank. Two have been in the tank for about 5 months, and the other for about 8. They all seem to have their crowns open a lot. Over the last few weeks I've noticed that the one that I've had the longest, the feather crown is getting smaller. Where the feathers were once maybe 2" long, they are now about an inch. Haven't noticed this with the other two. Nor have I noticed anything bothering this one.
I had a 4th that died about a month ago. Had had it for a few months, all was going well, then it tossed its crown, started growing a new one, but then up and died.
I thought FD's were one of the easiest things to keep! They are the only things I'm having trouble with. I squirt in some phytoplex 2-3x/wk. Parms ok (1.022, am=0, nitrite=0, nitrate=15, temp=75)
Thoughts?

 

[viper_930]

Have they just shrunk in size or do they not open fully? They may need more phytoplankton added, especially for a big tank like that.
Also, I would recommend getting your temp up to 80-84 degrees.

 

[fmarini]

feather dusters requires lots of phytoplankton for food. These worm tend to do well in large established tanks w/ lots of live sand and live rock, primarily because the surface area afford for a fair amount of microalgae and infauna.Unfortunately our tank are too clean for these guys.
If you'd like to save the worms. i suggest you consider daily doses of live or cyropreserved phytoplanktons. I suspect your not feeding enough phytoplex (i'd suggest you use something better like Dts or cryopastes). As for feeding them, Turn off your main pumps and allow the worms to feed for an hour or so, then turn the pumps back on. Currently the food is most likely being taken away as quick as you add it.