ATI Blue Plus T5 Fluorescent Bulb Combines the properties of a blue bulb (approximately 460nm) with an actinic bulb (approximately 420nm), producing an intense blue light with high PAR numbers and a light spectrum that encourages both bluing in SPS corals and fluorescence in capable corals. Helps balance a washed out/ yellow-hued tank. Recommended as a supplement to metal halides or in combination with Aquablue Special, Purple Plus, or other full spectrum T5 bulbs. Can also be used for dawn/dusk applications. (Similar to KZ Super Blue)