First growth on live rock, *** is it!?

[mkp523]

Just added my live rock a few days ago... on one of my rocks theres these purple tentacle things that retract into hiding if i make a sudden movement. On another rock theres this big patch of white crap, flat. I know i sound ignorant, because i am ! New to the hobby. Its exciting to see life growing!

[HaKs310]

Those purple tentacles sound like a star. The white patch sounds like coralline die-off.
You'll get more help if you can provide photos.

[djmuzzi]

Purple tenticles could be some type of feather duster.
The white "crap" could be bleached coriline.

[ANNIESREEF]

Those purple tentacles could also be the dreaded aptasia! Before you get rid of it, get a few more opinions but I saw it on my son's rock. If it is aptasia-get rid of it quickly! I am fighting it now...I agree with haks-the white stuff is probably die-off.
Good luck with reefing!