Yes I crammed some moss in there because I had more than I knew what to do with. I have removed it since then. I'll get some newer pics up soon. I am getting some growth out of the chain swords, they have sent out a bunch of runners. The moss is fanning out nicely from the tree limbs, but I started to get some brown algae. I have cut back the photo period and reduced the amount of excel, and it seems to be working.
I'm thinking about putting something tall along the back in places, like some corkscrew val or something.