The Giesemann Super Actinic T5 Bulb emits a powerful, pure actinic spectrum which produces a white/violet lighting effect. Recommended for marine and reef aquariums, this long-lasting bulb maximizes the fluorescence of your beautiful fish and corals, while promoting active coral growth. It provides exceptional color stability by using high quality phosphors, and makes an excellent light supplement for an existing metal halide setup. Made in Germany.