What is this??

[Beachbilly]

Something weird on my torch. Same side as the barnacle grayish fussy growth of some kind. Any idea of what it could be?

 

[Tahoe61]

If it's not physically moving I would be inclined to say marine sponge.

 

[Beachbilly]

Ok its not moving. Is it going to be harmful to the coral?

 

[kevgib67]

I have greyish sponges in low light areas of my rocks and on the skeleton of one of my torches for a long time with out any problems. You could also scrub it off with a toothbrush if it’s bothering you.

 

[Beachbilly]

Thank you for the info, much appreciated. I think I'll leave it alone.