Red Sand Polyps are another hardy addition to your reef tank. The center will glow fluorescent red under actinic lighting. They are a true Zoanthid, and will grow on rock or in the sand. They do seem to like a solid surface to grow on, and placing them at the edge of your reef will allow them to grow up onto your rock. These animals need to be treated like a mushroom as far as lighting and water movement are concerned. Low to moderate light and flow.