purple bubbles-are they bad?

[goldielox]

I just noticed a cluster of purple bubbles(they color of coraline) on a rock.  There is maybe 8 or so clustered together.  Is this bad?  If so what is the best way to remove it...the rock is loose.   It is kinda pretty though.

[Hookup]

sounds like red bubble algae.  If that is in fact what it is then it is not good and best to remove them. Bubble Algae, as the name implies, is a bubble shape that can pop... releasing spores into your system that will grow into more bubble algae.  This can be problematic to plague proportions if not removed or controlled. 

The best thing to do is to remove the rock carefully, scrub it under hot water with an old toothbrush and put it back into your system.  Obviously this is not always possible.  Alternate treatments are the use siphons to "pop and suck" the algae off of the rock.  This method is dangerous and though worked for me, some people have had little success and increased their problem.  Alternately, you can look into various crabs who like to munch on the stuff.  I have an emerald crab that either keeps my green bubble algae eaten, or has wiped it from my system completely.... Ive seen "red emerald crabs" (wrong name) but they are red colored and eat the red-version of bubble algae.

Photos would help for a positive ID.  Certainly nothing to get worried about as it's fairly easily dealt with.