Even though you bury the runners in the sand,I think a couple of shaving brushes would look great in your system.Thanks Dennis,you have me thinking about adding some to my display too.
I got something very similar to the grape kelp at Citypets several months ago. It had about 5 branches and was about 6" tall. They had it in their $15 frag tank I think. I mounted it on my live rock and it stayed for a few weeks before it started breaking apart and I ended up losing it all. I guess it did not like my tank.