Dsr, Phan agreed with you and others in his last post, he stated he's used 50/50 and plants grew but he had the best results with 5k, which is close to what your arguing about.
I've personally used 50/50 lighing in a low light tank that is stocked with Russian purple guppies, but that is more for aestestics than anything else, but the plants still grow.
In the end the Kelvin rating is not really meant to determine the growing quality of a lamp, its just meant to tell a consumer what the light will like when in use. For example, GE 9325K PC bulbs should near the blue/white end, but produce some of the best reds and are nowhere near the lower end of the kelvin range, where red should be.
I've personally used 50/50 lighing in a low light tank that is stocked with Russian purple guppies, but that is more for aestestics than anything else, but the plants still grow.
In the end the Kelvin rating is not really meant to determine the growing quality of a lamp, its just meant to tell a consumer what the light will like when in use. For example, GE 9325K PC bulbs should near the blue/white end, but produce some of the best reds and are nowhere near the lower end of the kelvin range, where red should be.