If I switch to 12/12 and find a sex can I change back and keep vegging?

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can I do this, like switch to 12/12 and find a female and then go back to 18/6 to keep the foliage growing and to increase yield?

Yes, I usually do this if i am going to make it a mother for clones, or i take a few clones early and move to flower room and determine sex that way

cool, so saying tomorw I put my plants in the dark room at 6am and take it out at 6pm, and when I see preflowers or balls I can just either kill the godamn male or put the female back into vegging and continue growing without it flowering early?

sorry for all the questions but First grow, need advice, want to kill males so I can use more light for females.

Would it be better to go 18/6 after knowing the sex to give it a dark period?

whats the point... by the time your done sexing your plant it will be like a week and half into flower, and then take another week or 2 for it to revert back to vegg, a total of 3 and half weeks wasted, i dunno i always thought this was a bad route to take. If your looking for a mom just take a clone and flower that.

Remember though, any change in the plants natural life cycle will stress it, perhaps to the point of showing BOTH sexes down the road when you finally change the photo period again.

Are you attempting this because you are limited on space and want to get rid of males before they get too big??

yep, not enough space and I don't need the males really, I don't mind how long it takes for it to revert back, but I just need females. So would i work or not, and how bad is the stress?

i was always under the impression the stress was pretty bad, making some hermies in bad situations, nothing could happen but at the same time ever female could turn hermie. i would just leave them all until flowering and just do it normally. When u sex them u will have all the room they need for flowering. it should only take a week, and the plants grow the most in flower i wouldnt worry about the cramped space until then when they really need all the light they can get. maybe place the taller plants to the outside of the lights, organize the set up so that the males u might think are males will not shadow out some good females. Males are ussually taller, so if your growing a strain look for this. Although it could be wrong and some femals may be just as tall.