anthelia dying

[cilyjr]

all my anthelia is dying. 3 colonies in 3 different places. parameters are posted below. got any ideas?
the crown starts to decay. and in some places the stock detaches from the matt.

 

[redvipe2010]

What else is in the tank? Are you running carbon?

 

[dendro982]

Same problem, until placed one frag closer to the lights and away from strong flow.
May be they, as a xenia, require dissolved organics to feed upon?

 

[cilyjr]

i am blaming this on lack of trace elements. i hadn't done a water change in a while. about a month +. stupid me.