Coral losing flesh

[chipz]

Hi everyone, I just noticed that the mystery coral that hitchhiked in on my live rock is looking sad today. I'm not actually sure what kind it is, but I think it's a LPS. Usually the flesh on this thing is nice and puffy, and it has grown a nice "skirt" around the original nodule of coral polyps that came on my rock in the 10 months I've had it.

 

Today that skirt looks bleached, and the nodule is looking pretty skeletal. The other LPS (acans, trumpets, hammer) are all looking happy as clams, as is everything else in the tank.

 

Things that have changed recently in the tank:

-This week I added two new fish (Bangai Cardinals)

-Late June I added a toadstool that has gotten quite a bit bigger than the original size of 4"x4" that the previous owner told me the coral was at and now the leather could theoretically be shading the mystery lps, now that it's expanded. I can still see the lps when I look top-down, but the Steve's LED is centered in the hood and the coral is off-center towards the front. I was getting a PAR reading of 75-80 at the LPS location before the leather spread out more, but unfortunately have returned the borrowed PAR meter, so can't check that. Oh, and I've been running activated charcoal with the leather in there. In fact I just changed it on seeing the coral looking sad.

 

I'm in the process of testing my parameters. So far:

Temp: 82.6 F (high, but pretty normal for the tank, it's a biocube with a hood)

Ammonia:0ppm

Nitrite: 0ppm

Nitrate:0ppm

Salinity: 1.025

 

 

Other thoughts: asterina star? Cleaner shrimp? Snails or scarlet reef hermit low on algae? Sweeper tentacles from the acan located 2-3 inches away (but then why would the whole outer skirt be bleached?)

 

I can't remove the mystery lps from the rock, so I can't do a dip. I need to pick up test distilled water for calibrating my brand new (to me) calcium Hanna checker, and find instructions for using the alkalinity one. I should probably also test the calibration on my refractometer.

 

The tank is almost 10 months old, and this coral has thrived from day 1 up until now. I will be so sad if I lose it! Any ideas what might be going on and what I can do to fix it?

 

 

[chipz]

[Tamberav]

Do you run carbon ? Lots of leathers in there.

 

I think it's a favia. I would certainly test alk and ca. I am assuming you do regular water changes which should replace elements but it looks like you have lots if coralline in there as well that could suck it down.

 

Your tank looks very nice btw!