This started out as a small "sprout" on a piece of live rock I bought years ago. In the past year it's gown quite a bit. It greens up in the light and bleaches out in the dark. I've had some sprout out of my sand bed as well. When I've pulled it out, it seems to have a root system. It's not invasive and I kind of like the look of it. Debating on transferring over to my new tank. Any info would be greatly appreciated.