Trachyphylia dying. Not sure why.

[I_Got_Crabs]

Parameters are fine (testing salinity, alk, calc, ph, nitrate, phosphate, magnesium). All other corals (birdsnest, acros, montis, acans, zoas, blastos, frogspawn, alveopora, challice), all fine.

No others corals within fighting range and the side thats dying is the most protected.

Possible nippers - damsel fish and sailfin tang - but again, all my other LPS are fine.

There was a little sand on it earlier this week that I blew off with a pipette.

Two question:

1) What might have cause this?

2) Can I do anything to save it? Weirdly the rest of it is not retracted and actually looks healthly/happy from across the room.

Appreciate any the help!

 

[cojo8888]

Flow?

 

[DSC reef]

A few different things can cause this like alk swings, nipping, coral warfare. The rest of the trachyphyllia looks fine and the recession is in one spot so I'm inclined to think something bothered that specific part of the coral. Typically with chemistry or lighting you'll see the coral suffer as a whole. I would try an iodine based dip like seachem reef dip, place in low flow and watch it closely.

 

[I_Got_Crabs]

Flow?

Low. Also hasnt changed in 6 months. Had this coral for over a year

 

[DSC reef]

Another idea, you can temporarily place the coral on a PVC coupler to raise it above the sand just incase that might be irritating the coral.