Zoo Med 6,500K Ultra Sun T5-HO Fluorescent Aquarium Bulb, 39 x 36-in; Maximize your tank’s daylight exposure with the Zoo Med 6,500K Ultra Sun T5-HO Fluorescent Aquarium Bulb. This high-intensity light brings out the vibrant colors of your carefully curated tank. It distributes light evenly across your tank water’s surface and emits less heat than a metal halide lamp. Each bulb offers up to 10,000 hours of stunning illumination and is great for use in marine aquariums, reef aquariums and freshwater aquariums where maximum daylight simulation is required. Combine with a Zoo Med Coral Sun HO-T5 lamp for live coral and invertebrate reef tanks or with a Zoo Med Flora Sun HO-T5 lamp for maximum plant growth (each sold separately).