The arcadia marine blue actinic t5 lamp produces a spectrum which peaks at 420nm this is the ideal wavelength for enhancing the natural fluorescence that is possessed by many aquarium speciesr tips on useit is important when using t5 high output tubes that they are not powered by a unit containing magnetic wire wound ballast such as the standard arcadia controller instead they should be lit using a ballast containing a suitable electronic circuit boardr the wavelenghtoutput of flour