The Distance sounds right, you can control it the way your plant grows.if the next nodes are vry close together, and your girls are " dwarfing" then you got to rise the light. if they start to look leggy , you should lower the light. And if you are no near, your girls get a lightburn, leaves bleaching out. for me it looks atm the right distance, but you see them eery day. and droopy might be from to much water. I dont know how much your Girls get but more than 50 ml per day is the amount of what the Girls need atm... for mor questions feel free to ask me