20" lowest power for veg. Slowly increase power once flowering starts but not too rapidly.Nice looking plants bud! Gonna keep watching cuz prob rocking same light! Mines kingbrite 250 (236 draw think) with red/ir n uv wired separate! Only had over the plants about 6 days so far on 1st grow! May need some hanging height tips n power level if u can adjust yours like I can?! Mine just started on 9/13