Favia death by???

[Stang67]

The above coral has been removed and disposed of.
I am trying to figure out what happened that caused this. Parameters, fish, some weird critter?
It started about a week ago and has been killing it at an alarming pace. My first thought was brown jelly, then rtn/stn.
Parameters as of last h2o change on 3/6
35 salinity
77 f
Phos. .104
Ni 5
Ph 8.2
Alk 7.7
Cal 445
MG 1500

No real swings in the past month. Just difficulties keeping alk up and MG down. Using baking soda in ato for alk. No other LPS or sps showing similar issues. I am watching them very closely.
I am still new to the hobby 3 yrs in. Tank has been up for 2yrs.
Coral was a frag I won about 18m ago and I am sad I lost it. Hoping to learn what may have happened to avoid similar issues in the future.

 

[monkeyCmonkeyDo]

It looks like something stung it and it melted and or jellied up.
Sorry for your loss. U didn't try and frag and save any of it?
Looks pretty bad in the picture so I wouldn't blame u I guess. Lol.
D

 

[Stang67]

It looks like something stung it and it melted and or jellied up.
Sorry for your loss. U didn't try and frag and save any of it?
Looks pretty bad in the picture so I wouldn't blame u I guess. Lol.
D

I did try to frag it but it was attached to a barnacle cluster and the bone cutters I have were no where close to being strong enough. I do wish I had some kind of saw but I really don't need one. I thought better to get it our since I was spreading so fast.

 

[Stang67]

My nems have been on a killing Spree for sure and they have found some great places to foot in. I can't get them out and and I can't get them to move. They weren't close to this guy tho. Could an urchin started this?

 

[monkeyCmonkeyDo]

I think an urchin would have left a trail like a snail trail but a nem stinging it and moving through the night sounds like the nail on the head.
D

 

[monkeyCmonkeyDo]

E.g. the urchin woulda left a stripe. Not the whole colony
D