Coral placement is crucial for the health of frags and colonies alike, but it’s not just the amount of light the coral gets that determines if it thrives. A coral’s immediate neighbors can have the most significant impact on its health, as some corals don’t play nice, believe it or not. During the evening hours, many corals extend their polyps and other feeding devices in order to capture passing food items. Sometimes, these stinging cells can touch nearby corals, causing untold damage that can range from small tissue damage to entire coral loss. LPS corals with long, sweeping feeding tentacles are the worst, as their stinging tentacles are quite powerful and can reach great distances. So, when putting corals in your tank, make sure to pick the appropriate locations and be mindful of the direction of the water flow.