What might this be?

[Jledg]

I am new to the saltwater game and still very conscious about my tank and making sure everything is right and leading the goods and the bad. With that said I noticed this on one of the pieces of my live rock. I don't recall this being there before. Is this part of the coralline algae? Or is it somewhere type of life growing on my rock? Sorry for the low quality picture but it's right in the middle of the pic between the gap in the rocks.

 

[tomreefer]

are you talking about the purple? That looks like coralline

 

[Jledg]

I'm talking about the piece that branches of like a tree

 

[mr.feebles]

could be byrozoans. harmless. could also be branching coralline. also harmless.

it appears all over and in almost everyone's tank, regardless of what it is (I've seen it thousands and thousands of times). either way, harmless.