I always have found that birdsnest can tolerate and even thrive in lower light than many other sps. My green acro has been doing pretty well on the very side of my tank. I have a 6 foot tank and only a five foot fixture - it still does well even though it is out of the direct light. I have only had it a few months though so I cant say that it is the best spot for it. I don't recall where I used to have it in my past tanks.