Coral ID and Health question

[Koresample]

This came with some live rock I purchased and started off looking good (all green and where the thick white bands are it was darker green). I have changed my lights from PC to LED (2 X 12" Vertex Illumilux Marino Blanco). The was knocked off the rock it was initially on one night (I am guessing by one of my snails) and a couple days later started looking like this. You can see its sweepers out in this image so it is still alive, but I am not sure what kind of coral it is, or what is wrong with its health. My tank is a 6 gallon nano, 125 gph flow, 77 degrees, sg1.025, nitrate, nitrite, amn all 0, ph 8.2, 77f. I do a 15% water change every two weeks with h2Ocean salt and my lights are on 12 hours, off 12 hours. All my other corals (open brain, Acro, shrooms, frogspawn & bubble) are all doing very well. It is located near the bottom of the tank but that's only about 10" down. Help!

http://i199.photobucket.com/albums/a...e/IMG_2062.jpg