time to change bulbs

[Just Jim]

I've been using the 250w 20k xm bulbs for almost a year now, and it's about time to get some new ones. I was thinking about changing to the 250w 15k xm bulbs. I really like the 20k but not much growth. Anyone else using 15k xm's? Is the spectrum still blueish.

[BRISK495]

I beleive 15K XM have a pretty low Par, so if you want growth, you may want to stray away from them....10K XM would be the way to go for growth

[cmondo]

Brisk is right, that is pretty much the way it works........To put it lightly, 65k's for the quickest growth and 20k's for best color all depends on what you are looking for. Goodluck.

Chris