The most frequent question I get is "What type of macro algae is that in your refugium?" It's feather caulerpa (C. Sertulariodes), and I've been growing it for at least 8 years. I've used a few others, but this one has been the dominant one. From time to time I'll pull a few handfuls out, usually when someone needs some. I thought I'd clean it up but noticed the tiny pods, bugs and other items so instead I grabbed my camera. Here's a close ...