ATI 24W Coral Plus T5 High-Output Fluorescent bulb combines the properties of a Blue Plus (~50%), Aquablue Special (~40%) and Purple Plus (~10%) producing a bulb with a cool, crisp white color with hints of red and blue. The higher blue component compared to an Aquablue Special produces better fluorescence in capable corals and the red component is excellent for color rendition. Approximate color temperature: 15000K+. Recommended Use: as a stand-alone bulb or in combination with Blue Plus, Purple Plus, True Actinic or other supplemental T5 bulbs.