Cladophoropsis? How do I get rid of this algae?

[Myka]

That is probably Gelidiopsis spp. algae. Cladophoropsis spp. is green.

Diadema Urchins and many Tangs will usually eat it, although both are suited to large aquariums. You could try a Tuxedo Urchin and/or Scarlet or Blue Legged Hermit crabs if the tank is smaller.

[nerdz]

Is it on a rock you can pull out? If so, you can treat it externally with peroxide. I haven't tried it on this kind of algae but every other that I've tried has worked.