I recently purchased both chaeto and fern caulerpa from reefcleaners.org. The caulerpa looked half dead when I got it. I don't think it's grown at all yet, but I can easily see that it might break down and cause excess nutrients. At the moment it's in a bucket with other macros, LR, and CUC, waiting for me to partition my sump/fuge, so I really don't know if it looks better or worse. It's been in there for a few days.