The Flora-GLO linear fluorescent light bulb is a T8 normal output bulb with a color temperature of 2800K, Color temperature for fluorescent lights is assigned a value based on a human color perception that matches the color of the particular lamp, It fits all suitable standard and electronic ballasts, This fluorescent bulb generates a strong photosynthetic spectrum that is ideal for stimulating strong plant growth, The Flora-Glo Fluorescent Aquarium Bulb Features and Benefits:, - T8 bulb fits standard and electric ballasts, - Energy efficient, - Close placement to water surface offers the potential to maximize light entry into the aquarium, - Generates a strong photosynthetic spectrum, - Ideal for optimal plant growth, 18"" length, 1"" diameter SKU: RCHG0488