I think they state 4000k as the temperature of it. This looks like a sort of a multipurpose bulb with the temp right in between the optimal for both vegging & flowering. Optimal for vegging is in the ballpark of 6500K and flowering is 2700K.
doco Reviewed by doco on . MH bulb Just wondering if this bulb would be okay for flowering. http://www.jpghosting.com/showpic.php?image=sunmaster400MHbulb_baeb356eca98c7c074fe27a50b86a796.jpg http://www.jpghosting.com/showpic.php?image=sunmaster400MHbulb2_7794e0b82755a5e0c07c7df8afa2b425.jpg its 4000k 400 watts pls help. Rating: 5