Officially, Galaxea is a large-polyped stony coral (LPS), in the same general category as Torch, Frogspawn, Hammer, Bubble, Plate, and similar corals. Among the LPS corals, Galaxea has relatively small polyps. Small-polyped stony corals (SPS) are in a league of their own with respect to light, flow, and mineral nutrient needs.
Enjoy the ride,
Dan