What is this algae on my pipe organ and how do I get rid of it?

[mandyplo]

Hello, I recently purchased this frag off of a friend in town and it appears to have gathered some algae buddies in our tank.

Is this algae harmful, should it be removed, and if so how would I go about removing it?

Here is a picture:

http://i.imgur.com/5rCNl.jpg

Thanks in advance!