Live Rock, Gravel and Light?

[tinpusher]

I am designing a sump in an old 50 gallon I have laying around. 33% of the sump will be a refugium that can be viewed through a window in the cabinet and 50% will be reserved for overflow in case of power loss. The refugium will be lit but not the reserve section. The reserve section will have a few inches of water in it and I am thinking of adding an inch of live sand or a few small live rocks to help filteration. My question is does live sand and or live rocks stay alive in the dark or with minimal light?

Thanks