Be careful when placing other coral around those Galaxea, as they have long stinger tentacles that will extend several inches at night in search for food. If they sweep across other coral in your tank they can sting and cause serious damage to the coral it stings. It also needs a high level of light to perform photosynthesis which is where it gets most of its nutritional needs. It also needs a decent level of flow, but not a high level of flow otherwise it will develop brown jelly disease.