Anyone Know What These Are on this Live Rock?

[FishBone]

I have a buddy of mine who set up a tank awhile ago and always was having problems.. Most of his fish died from ick and now the tank is empty.. All that is left is the live rock which he wants to get rid of..He spent some good money on it and has about a 100lbs. Its all purple Coralline Live Rock.. He will give it to me but im not sure if i want it.. the rock will have to come out soon because he barely has any flow in the tank and he isn't taking care of anything.. I have a couple photos of some thing growing on the rock and was wondering if someone here knew what is was .. They are white and fuzzy/feathers.. Ive had feather duster/tube worms in the past and this doesn't look like them at all.. they are not in a tube.. Ive also had those small pineapple sponges and they are not like this either.. I'm starting my tank back up but don't want someone else problems.. Any help would be great thanks so i can get the rock out sooner than later if its worth it..

The photos arent the best but it was hard to get a good photo because the glass was pretty dirty,

 

[reefstarter]

looks like some sort of sponge ,

 

[FishBone]

Thats my thought to reefstarter.. Sponges are ok. My plan is to take out the rock and clean it the best i can, if these are only sponges. Ill put the rock in a rubbermaid tub with a powerhead and do a few water changes before i put it in my tank

 

[Bobbofin]

I had pineapple sponges in my sump but none in the tank. Sponges, pods, etc are a sign of a healthy tank unless they're going crazy. I have a SPS/LPS tank so my sponges only grow in sump. Too bright in main display, they're low light specimens.

 

[FishBone]

That's where my pineapple sponges were. In my sump. Still not quite sure what these ones are