Originally Posted by revhtree
Could this be the problem with the xenia?
Could be but I doubt it. As Mojoreef said, it usually remains with the coral colony it's affecting. I had a similar issue with violet/green/pink zoo's which almost destroyed the whole colony. The only thing I could do was frag
(break) the rock of an unaffected area which prevented the spread. Nothing too close to the fungus should be fragged so be sure there is a well defined gap between the healthy polyps and the dieing ones.
You are actually fighting a war on two fronts. The affliction is smothering the coral causing die off. The die off will affect the health of the adjoining polyps making them easier targets for the fungus to get a stronger foothold. Dips are just as damaging to most zoo's as the problem your treating so quite honestly it's usually much better to cut your losses and try getting a few good frags
in hopes of saving at least one or two.
Bear in mind that if you can save even a small portion, it's a successful venture. Zoanthuds will regrow quite easily under the right conditions.