Is this a Coral or Algae?

Hi,
I'm brand new to this forum and very glad it's here. A little history... I used to have a fish-only 55 gallon saltwater tank with great success. That was 15 years ago. Now I have a 10 gallon fish-reef, going on almost a year now.

Reef tanks are really new to me and was hoping for some advice...
A few months ago I purchased a very interesting piece of liverock. At the time it only had two types of green algae/'seaweed' (grape caulerpa & some grassy type) among some tiny anemones, green pollops & 2 very tiny brittle stars.

In the past few weeks, however, I noticed underneath the suspended rock was some growth that looks a lot like roots of a plant (only this is very white in color) sticking thru the holes of a pot, however, it is accompanied by many hollow transluscent tube-like structures (also white) with open ends sticking straight out (about 1/4" long).

I have not been able to identify this. The growth seems to be picking up, especially since I introduced weekly vitamin supplements (Coral-Vite). This stuff has started to spread to the top of the liverock and has even started sprouting on my fake coral pieces; now and I am concerned that it may become intrusive and choke out the valued life in the tank. But if this is something interesting, unique or desirable, I would like to know.

Do you think you could ID this?

Thank you so much in advance!
GinaD

Tube worms?

Thanks for your reply. I'm not familiar with "Tube worms" - do they look like white roots? I'll google it before I ask too many stupid questions... be back soon...

Ahhh...

Ahh...Tube worms! Oh yes - feather dusters (of which I have two types in my tank) are a type of tube worm and with all the photos I've just seen it doesn't seem like that is what I have. None of the feather dusters I have or the photos I've seen have 'root' like growths at the base - they just end abrubtly. Besides, I may have failed to mention that the hollow tubes sticking out are transluscent and I can see that they are very hollow (no worm). Thanks for the suggestion, however! It was very very good especially considering you are going by my description and no photo!

Got it!

FYI: I got an answer to my question. I picked some of this stuff off and brought it into the petstore where there are some very knowledgeable saltwater guys. Two of them said it was a type of algae and shouldn't be harmful. However, if it does become intrusive to my green algaes I can just pick it off. One of them said he had this in his tank.

Thanks for your help, YoFishboy!