encrusting

[pulpfiction1]

i seem to have something encrusting this rock with zoa's on it.the orange zoas are being covered over as well,and the white that appeared over night on the end is hard to the touch,was thinking maybe the xenia beside it was trying to move onto that rock so i have moved the zoas some distance away now,they have been side by side for a long time now,any constructive ideas?the picture is bluer than it actually is,dunno why

 

[AdInfinitum]

I had the same thing come up the back of a sun coral rock and kill a bunch of polyps.  I thought it was a fungus but found the edges quite hard so maybe an encrusting sponge?  Since sponges can't survive exposure to air, I pulled the rock out of the tank for maybe a minute ( no problem for sun's and I think zoas are even more tolerant of air).  Fungus or sponge, the air treatment killed it off.  Might work for you if the piece is one that you can get out of the tank and certainly won't hurt to try.

 

[Darryl_V]

definitely sponge....