There are many differences in where they grow in nature and the corresponding lighting conditions they need in order to survive. Corals are highly adaptive to different lighting conditions, but some are more sensitive to change than others. It takes time for a coral to acclimate to its new environment, and care must be taken to help the organism adjust. This is especially important with some of the very intense lighting systems, like metal halides and T-5 fluorescents. Some corals, when not acclimated properly, can actually be "sunburned" by the artificial lighting, which opens the door to infection and possible demise. Place your new coral on the bottom of the aquarium in the substrate until the coral adjusts to the new lighting. A good sign that the coral has adjusted to the new system is when they appear fully expanded and display full coloration. At that time, the coral can be moved to the desired location. Continue to monitor the coral's response to its new location, and if its coloration and expansion appear to decrease, relocate the coral to a lower position.