What coral is this and why has it died?

[ShelaghM]

I purchased this coal as a frag which at first seem to be dieting, but what was left I stuck to a rock and it grew and grew for about eight month. It started to over grow another coral so I broke of a bit and stuck it to the other side. As you can see from the photo it became a lively group. It was green by the way. Then suddenly it turned white. I have no idea what it’s called but have seen then growing in quite a few tanks at Lfs. Can anyone advise me as to why it died and what it’s called. All my parameter are within the Red Sea advisory. My latest Triton tests all came back fine?

 

[ApoIsland]

Looks like a plating montipora to me. How long did it take to totally die from the first time you noticed it starting to go downhill?

 

[guylaga]

Appears to be Monti Cap, usually they are pretty hardy and looks like it was thriving.

You must have had something go awry in your tank, how are your other corals looking?

Check your Alkalinity, Salinity and Temperature again, you said parameters "are within the Red Sea advisory" but didnt post what they are.