18/6-12/12 (when)

[sc0usa]

hi ppl

how many weeks/months do i have to wait b4 swiching my light cycle to 12/12,im using hydroponics and started from seed,thx guys!!

[Proof]

depends it aint how long u had them for its the height of the plant u can proberly change the light cycle to 12.12 when they are about 20" tall.

[Tetrahydra]

The way I know it is to let them at least get through the seedling stage, about 45 days. From there change the lights when you have reached 2/3 the height you want. Cannabis will continue to grow about !/3 the size of the plant after flowering has started.

[sc0usa]

ok cheers guys,got a while 2 go yet then :)

[rnf232s]

Wait to go to 12/12 once you see the signs of pre-flowering. There will be early signs of sexual development and stuff. After this starts you can keep it 18/6 for longer or start 12/12 a little after this starts.