<a href=showthread.php?s=&postid=15422063#post15422063 target=_blank>Originally posted</a> by Maivortex
Looks like RTN (rapid tissue necrosis) . RTN is prolly the only thing that could destroy that much of a coral in 30 hrs. If you can get chlormaphenicol, Quarantine the coral in a separate tank with 20mg/L of chlormaphenicol for 3 days . Each day do one iodine dip. Chlormaphenicol can be hard to get but it is very effective against RTN. In anycase I would frag it. Very sad to see.
Wow, I thought to myself "surely chloramphenicol can't cure RTN." But thanks to the literature, turns out it can, or at least may be able to.
RTN correlates with higher numbers of
Vibrio spp. bacteria in the coral tissues.
Vibrio is sensitive to chloramphenicol, so could work. As mentioned above, the trick is going to be getting your hands on some. I have no idea how to do it as a private individual -- when I need it I just order it through the university credentials, but then again I have a legitimate lab use for it
Good luck with your coral, it really sucks to have a big colony like that go.

I suppose the best thing to do is to frag frag frag and try to get ahead of the problem.
"Bacteria associated with the rapid tissue necrosis of stony corals" G. M. Luna, F. Biavasco, R. Danovaro. Environmental Microbiology, 2007:9:7 (p 1851-1857).
"Comparative Trial of Tetracycline, Chloramphenicol, and Trimethoprim Sulphamethoxazole in Eradication of Vibrio cholera El Tor" R. A. Gharagozloo, K. Naficy, M. Mouin, M. H. Nassirzadeh, and R. Yalda. British Metical Journal, 1970:4(5730): 281"“282.