it must be different manufactures because i have a giessman midday and a lifeglow 2 both are about the same kelvin and one is noticable more white and the other more yellow. both ran off the same ballast and fixture.
How does the green spectrum compare between bulbs? Life-glo II has a large spike in the green nearly 100 intensity which will provide a much brighter and whiter light.
Thanks everyone for awnsering my question. Neo that makes sence about the photosynthesis, lights are so expensice I hate buying them, BUT I would like to see a grass bed on the bottom of my tank ! ! !