Please identify

[Ettabon]

I've had this in the tank for a bit. I asked my son he said it's not much to worry about but I'd like to know what it is. Thanks for any help I can get.

 

[Soren]

Which part of the picture are you asking about? I see what looks like green hair algae and coralline algae on the rocks with a traslucent white sponge in the center and an aiptasia anemone (or several) in the top right.