I hope you named that fish Bob the Builder! He is a machine!Although being up off the sand on a rock doesn’t guarantee safety in this tank. He is currently burying the zoas which are up on a rock.
I have a green hammer that gets a lot of light from a metal halide and grows like a weed, you can see it in my build thread. I have mine right at about the upper third of the tank, but I’m sure there’s no need to move it that high! I wouldn’t be afraid to elevate yours onto one of those rocks, maybe 8-12” off the sandbed? Just keep it out of direct flow and you should be fine!
some before and after pics and under blues