Zoo Med Aquatic Reef Sun 50/50 Compact Flourescent BulbZoo Meds Reef Sun 50 50 Compact Fluorescent Bulbs are a 50 50 combination of 6,500k trichromatic daylight phosphor and 420nm actinic. 50% 6500K trichromatic daylight phosphor 50% Actinic 420 phpsphor For marine reef ranks, nano tanks and "subdued light" aquariums These bulbs provide exceptionally high intensity full spectrum illumination and are ideal for marine aquariums, reef aquariums, African Cichlids and Discuss. Size: 5" Watts: 10