50/50 Combo lamps combine the power of Deep Blue's 10KK Daylight & Actinic-03. Triphosphor fluorescent for excellent color rendition on daylight tube & 100% blue phosphor that peaks at 420nm on actinic tube. Powerful, 10,000 Kelvin Daylight & Actinic-03 PC fluorescent lamps ideal for both freshwater and marine aquaria. Provides light vital to healthy growth of photosynthetic corals. Simulates the blue hue of deep water & tropical daylight for all purpose illumination. Universally sized and compatible with most PC lamp systems. Low profile, space saving design. Use with electronic ballasts for efficiency and extended service life.