Coral Sun High intensity actinic lamps from Zoo-Med give off strong blue light from the short end of the spectrum, peaking at 420 nanometers. This output closely matches the absorption peak of blue chlorophyll used in photosynthesis by plants and beneficial algae, especially zooxanthellae algae, which live symbiotically with reefs and are needed by many corals and invertebrates for proper growth and survival. Actinic lighting is important for deep water fishes, as it is the blue wavelengths that penetrate water the deepest. Creates a pretty sparking bluish lighting effect. Coral Sun lamps are ideal for marine aquariums, reef tanks, and African cichlids.