I'm growing under 1000w gavitas (with gavita controller) and the lights are at 10' 2" (plants on 26" high table). The plants are 18-21" tall. Right now I have them under 650w.
How fast should I increase the light intensity to 1000w? Thanks.
Depends how much of a hurry you are in mate. Most of us tend to use less wattage for veg then crank it up full for bloom, or once the footprint of the light is fairly full.
They'll grow faster under 1000w assuming they're big enough to handle it but you might find they get a bit hard to control.