True Actinic 03 Blue provides light in the 420 nanometer range that reflects color pigments in organisms such as corals, fish and invertebrates causing them to fluoresce glowing colors. It's spectrum resembles that of the absorption peak of chlorophyll-a which is the most important pigment found in plant cells.
Coralife True Actinic 03 Blue Compact Fluorescent Lamps:
Fluorescent lamps for Marine Tanks contain specific spectrums of light for marine fish and invertebrates.
Actinic bulbs contain a wide spectrum of blue light and pare particularly good for live plants and marine corals, anemones, and invertebrates. They are used as a supplement to other bulbs that give better visual appeal.
Daylight bulbs simulate natural sunlight and are a good choice for most general aquarium applications. They provide a natural color to your tank and are a good source of light for freshwater live plants.
A combination of lights is often used to achieve all of the benefits for all of the aquarium inhabitants as well as give the viewer the best visual color. If using more than one light tube is not possible, the 50/50 bulbs provide the best compromise in most marine situations.