Quote Originally Posted by headshake
he said 150W actual wattage. the K (short for 1000) behind the 2700 (2700K) indicates the color spectrum. 2700K is actually in the red spectrum, 6500K is in the blue spectrum. 2700K is better for flower, 6500K for veg.

using watts is not the best idea. watts are merely the consumption of power. this doesn't take into account the efficiency of the bulb.


-shake
The K is actually for Kelvin. It measures the temperature of the light emited from the bulb.. And, higher kelvin values mean less lumen output from the bulb.