The Aqua-GLO T8, 20 W linear fluorescent aquarium bulb generates an ideal fish colour-enhancing spectrum and delivers a strong photosynthetic range of light very capable of stimulating vigorous plant growth. This normal output bulb has a colour temperature of 18000K and fits all suitable standard and electronic ballasts. It is an excellent bulb to combine with Power-GLO and/or Life-GLO bulbs in most planted aquariums. Size: 61 cm (24 in). T8 Bulb 20 W 555 Lumen 18,000 K 9,000 Hours