Light

How long do you kno when to switch to 12/12 lighting about how many weeks is it, im just wondering cuz mine are about 3 weeks and I got them under just flouro tubes but for flowering im gonna use a 400 watt HPS but Im not gonna get it till about a week or 2 before flowering

how high are they m8 i made the mistake of letting mine get to 26 -28 inches tall before flowering now they attack the ceiling are stretched and i have to tie em down so i have learned that at about 12 to 14 inches next time they going on 12/12 hope this helps