True Actinic 03 Blue Fluorescent T-5 Lamp - 18W - 30 in.
ESU's True Actinic 03 fluorescent bulbs produce actinic wavelengths at 420 nm, ideal for supplementation to your daylight lamp for fish-only saltwater or low light reef tanks. Actinic light is the blue end of the spectrum, used by marine organisms because it penetrates water further than other spectra. The blue glow displays your saltwater tank to its fullest potential.
T-5 fluorescent bulbs install in T-5 fixtures and are more powerful, compact and energy efficient than T8 or T12 bulbs.