I'm really so far behind all of you on suggestions and ideas, so this may not even be relevent now, but... I've been looking through all the past forum posts to see if there has been much mentioned about this. There were a few a year ago and I thought maybe it might be interesting to bring up again.
About 15 years ago I had a 60 gal. saltwater tank. It was a live rock, gobies and damsel tank with semi-fine crushed coral for the bottom. The colors of the fish were wonderful, but I really wanted something green in my tank. My local aquarium shop offered me what he called a 'weed' and if I wanted to take the time to control it, it was probably what would do the job for me. It was called Caulerpa taxifolia and was very pretty, a lively green color with long frowny leaves. I took home a 3x3 patch of this and wove it through a large piece of dead coral I had as decoration. Within 6 months that thing grew all over and through the coral, swaying gently and adding the perfect accent I was looking for into my saltwater world. It was easy enough to pluck off tuffs of it while cleaning the tank to keep it down to the shape and size I wanted. My local aquarium shop also took back anything extra (for free though)
Anyway, here is a more scientific look at this lovely 'weed', if more information and some nice pics would be helpful to decide whether or not it's a possible candidate for future add-ons?
Sorry to post a link rather than images, but I'm not sure who would allow their photos to be shared here or go about getting permission, so heres the sites url instead:
http://www.sbg.ac.at/ipk/avstudio/pi...t/caulerpa.htm