Power Glo?

[VidVid]

I recently purchased a 30 watt T8 Hagen 'Power Glo' tube that runs in correspondence to my 20 watt, believed to be 'power glo' tube as well i think (giving a combined 1.6 w/g)... I really didnt take notice in lighting since im just begining a planted tank but now after looking at the printed box, i noticed that the power glo emitted a 18,000 K colour/light spectrum. It said it was a high intensity aquarium lamp suited for freshwater, planted aquariums but also noticed that it is also ideal for saltwater aquariums and invertabrates...
What is meant by 18,000 K??? I heard that such a high 'K' rating promotes algae, but does this also mean it promotes plant growth just as well??? Does the high 'K' rating for both my tubes influence the the intensity in terms of wattage and does it help the plants greatly in terms of their light requirements (as a result of the high 18,000 K rating)???
Thanks for any responses...

 

[nukeonekitty]

They are good bulbs, I have two in my tank. My plants aren't growing super fast, but they look great!

As for K rating. K means Kelvin. It is a SI heat measurement also known as Heat Transfer Coefficient. It is a measure of the rate at which heat energy flows through a surface.