I just bought a 4 foot, 2 bulb T5 fluorescent sunblaze fixture and it came with two 54w starcoat cool white bulbs 6500k or daylight, it says both on the box. The info I got from a friend is to use 1 cool white and 1 warm white for vegetative growth but I've read different while looking for a better anwser. I already own 1 warm white 3000k. I just don't know if I should use it or not. Thank you very much for your time.
T5 Fluorescent Lights
Certified GKH Gardening Expert
For optimal growth, yes, a warm and a cool are best, as they will provide both the blue and red light spectrum the plants need. That being said, for the most part, especially if you are just growing seedlings under the lights, cool bulbs alone will work just fine. The plants grow fine and do not suffer from the lack of the red spectrum for the relatively short period they are under the lights. I would only worry about making sure they get warm light if you plan on keeping them under lights for many months.