Description : 08623 Coralife 10000k T5 lamps are purified super-daylight lamps with high-intensity lumen-per-watt output that simulates the midday tropical sun. Each bulb contains rare-earth; color-enhancing phosphors that emit sparkling; blue-white light rays. Great for both fresh and salt water aquariums. Efficient T5 lamps provide as much or more light than comparable T8/T10/T12 style lamps; while using less wattage and saving on energy costs. Designed for the Coralife Mini Aqualight T5 and other compatible T5 fixtures. The 6 watt bulb measures 8.875 in. long. Not compatible with T8/T10/T12 style fixtures. For more information on lighting; please read our Aquarium Lighting Guides .