switch over size

[michaelskunknasty]

is it true that plants double in size in the flowering stage? Should I switch over to flowering light when they are half way up my grow box? Also how close to a 400 watt hps can plants get W/o damage?

 

[bizzy323]

they can double or even tripple in size when flowering. I have my light at about 11" from the top of my plants and it seems fine, but I will drop it down to about 8" after awhile and keep it there. Do you have good ventilation in your grow room? also do you have a fan blowing on the light?