12/12 light cycle

Can you start the 12 on 12 off light cycle at any time? I know it is recommended to start between 20-30in or something but what happens if you start the 12 on 12 off when their 10in? Will it just produce less weed?

you can do 12/12 anytime you want it is your choice for instance i am experimenting with 12/12 from seed..this is done alot

usually u will start flowerin stage in 4 th to 6th week of veg then go 13 11

From seed: pop seeds and put sprouts under lights on a 12/12 schedule until they show sex. after clearing out males (around week 4ish) switch to 24/0 to veg until they are the appropriate height for what you need them for (if you want to finish with a 6 ft plant i would recommend vegging plants until they reach 4 ft. (2/3 rule)). once plants are appropriate height they are switched back to 12/12 to finish. Avoid changing light schedules too much or you may "stress" the plant which sometimes result in herms.

There is of course alot to learn about light cycles and many different techniques that work. this is a simple method with good overall results which has worked for me.

Like rene said, you can start 12/12 whenever you would like. 12/12 is usually started when the plants either show their preflowers, or when they will grow to the size you want. And what I mean by that is, when the plants enter the flowering stage, they begin what is called the stretch. This is when they finish growing vertically and start to use all their energy towards making flowers. The stretch is usually about the first 3 weeks of flower, then they just explode. They usually grow 2 to 3 times the size they are when you start flowering. Of course it varies strain to strain, but this seems to be the general concensus for most strains. So if you want a 20-30in plant, 10inches is a great time to start flowering. Its all about how much space you have to let the plants grow. Hope this helps you. Happy growing