The spots that you see on the glass are on the outside of the back of
the aquarium. They're caused by spray from the top of the skimmer. Yum.
The green filimentous algae you see is a slow growing, extremely tough
algae. I don't have anything that eats it, and a stiff brush has no
effect on it. I can remove it only by grabbing tufts of it with strong
tweezers and tearing it off.
Here's a closeup of my dying gorgonian. The front branches, at least,
are roughly in focus. I suspect that this gorgonian is not
photosynthetic, and is dying for that reason.
The tip of this mussel has three polyps of a stony coral that came on
the rock. I haven't noticed any growth in the 8 months that I've had
these, but they don't appear to be dying either.