What Type of Algae is This?

[Jason777]

I think it's possibly a type of Caulerpa racemosa but not sure, never seen one flat like this. The tops are flat discs and are blue/green and somewhat variegated, almost like a watermelon mushroom.

Best way to get rid of it? Thought I should ask before trying to remove it and possibly making it worse.
Sorry for the poor photo but it's in the back of my tank. I'll move it if we need a better photo.

 

[saltyfilmfolks]

Mermaids cup maybe?

https://en.m.wikipedia.org/wiki/Acetabularia

 

[KJ]

Look like Mermaids cup (Acetabularia acetabulum).

 

[Jason777]

While the caps look a lot like mermaids cup the research I've done leads me to believe that those grow on individual stalks that each attach to the substrate. The stalks of this were individual but coming up from a runner with a stalk every 5-10mm or so, like Caulerpa. I should have taken some more pictures but since I had to disturb the coral I just pulled it out and removed the growth. Now I'll have to wait and watch and see if it grows back.

Just a little background on conditions; The tank is about 2 years old and Salifert says NO3=0 and PO4=0, Hanna Phosphorous ULR shows 6 which works out to 0.018 if my formula is correct. There is a little bubble algae and I've been trying to control it with low nutrients, water changes, and a little GFO, a battle that has been ongoing for about a year.

 

[cristata.reef]

Hmm the caps don't have that distinctive concave shape I look for in Acetabularia. I they appear to be more convex and rounded so I will play the devil's advocate and say that this is Caulerpa racemosa var. peltata