Unknown plant...

[bbrklynn]

Can anybody tell me what this is and/or how to get rid of it without damaging the polyps underneath...
When I got it- 6 weeks ago... this is how it looked...

Today...

 

[Reefing Madness]

Looks like 2 kinds there, Caulerpa and Grape Algae. Both are a Macro Algea. And you need a pretty big clean up crew to keep that outta the tank, or to clean it up also.
Snails
Sea Hare
Urchin
Tangs

 

[bbrklynn]

My reef is too small for tangs...
I do have a few large turbo snails, but they don't touch the stuff...
They do a fantastic job on the rest of the rocks with the smaller algae and on the back of the tank though...

 

[bbrklynn]

The rock underneath the caulerpa is almost completely covered in button polyps...
I don't want to damage them.

 

[Tahoe61]

Caulerpa racemosa and Caulerpa prolifera, I believe. Both extremely invasive as you have found out. Manually remove/rip it out. Tuxedo Urchin eats it I believe.

 

[Reefing Madness]

Urhcin, Sea Hare, there are plenty of others out there that will tangle with that stuff for you.
You could possibly borrow a 2 Barred Rabbit fish then give it back when its gone
Once in the tank, it kinda takes hold. Your going to need one of those guys to remove it though.