Sorry I have to disagree about Xenia, especially the brown or silver tipped being a delicate coral.
I have ripped it from a rock, dropped it on the floor, flung it against the wall, left it for 10 min and then threw it in the tank only to have it out and pulsing the next day.
I take several hundred dollars a month worth to a LFS 2 hours away in Zip lock bags and it is out and pulsing in the bag 15 minutes after the tank lights hit it while it is acclimating to the temp in their tanks.
The tempature in my propagation tanks drops on average of 10 degrees per night (81-71) I rarely, if ever, change any water other than what is replaced from a sale and top off is done every 4 or 5 days. I only mention this because it has been my expierence that Xenia is largely unaffeacted by even moderate changes in temp or salinity and will grow under about any lighting conditions.
A few key things for Xenia (not all things and in no particular order)
- nitrates below 10 ppm
- stong enough lighting to support most any soft corals if you want it to pulse
- moderate to strong current
regular water changes or iodine suppliments
healthy stock to begin with
Xenia IMO is one of the hardier soft corals/polyps out there and I would look toward water conditions or large PH swings (even a depressed PH) and then to the health and condition of the piece first. While Xenia can take a few days to acclimate I think 2 weeks is to long and something else might be a miss.
FWIW
SiF