Fuzzy stuff on LR?

I've had a 20 gal. with LR running about 4 weeks and have a small case of red hair algae I'm taking care of ok. One large piece of LR has a lot of what looks like a grayish fuzz on it. It hasn't spread to any of the other LR and it doesn't look like a hair algae. The water current makes it move in the current even though it's only about 1/6 to 1/8 in. long. Some small pieces will look like tiny bushes. I used a glass scraper to poke around at it and it can be scraped off easy so it must not be attached tight to the rock. The water tests good in all tests and I have a skimmer on and HOB filter,and run lights about 9 hrs. a day. The stuff is not light gray but is a dark gray,with some coralline starting to appear on top of the coral that gets direct light.
Anyone else seen or had this before?
PS. There are holes in this piece of LR and this is also in there even where it is away from the light.

 

Does it look kind of like a white film. Does your water smell funny? It could be that the LR was not cured enough. If this is the case then the white web is the LR dying off. It will come back, as the curing process is taking place in your tank. If this is the case, don't put any livestock in there until it is gone and the water smells like the sea not like dead bodies in the sun. A damsel might be ok, but other than that is risky. Hope this helps, common syndrome with new tanks, as well as when "uncured" LR is put in.


Good Luck,

Aaron.

P.S. If you have a digital camera, post a pic to help 3reefers diagnose.

 

The water is fine and smells like good ole salt water and no ammonia or nitrites,etc. A snail cleaned of a section about a week ago and now coralline and other algae are appearing in that spot. The stuff just looks weird.