How soon can you flip to 12/12?

Ive been Googling this and the answers so far - as is so often the case with our hobby - are all over the place. I am having a hard time telling if there is any real science behind any of these answers or not, but I trust you guys more than other sites, so Im going to ask you guys for advice :slight_smile:

Some people claim you can go to 12/12 from seed.

Others say wait till after you see pairs of leaves, or three or four or five nodes etc.

Others say wait till you see pre-flowers.

Im having problems with my roots seriously outgrowing the space in the root chamber (HPA) after 5 weeks of veg, so I really need to start sooner than that. Im thinking two to at most 3 weeks is going to be it if I want to keep the roots happy and not crunched in or eating my spray nozzles.

I would like to hear from you guys about the pros and especially the cons of flipping early, and how early is truly safe and/or wont hurt final product too much.

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I think there’s no benefit to switch until they are sexually mature ( preflowers and or alternating nodes) if starting from seed.
If they are clones they should be ready to go once established.
But that’s just like my opinion man✌️

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From what I’ve been reading up it’s generally best to let a plant that has a male and female expression to fully express sex before flowering.

From what I have been able to understand it’s much better able to handle stress when it’s hormones are stable.

Feel free to ignore what I said though as I’m still learning myself. I do my best to retain what I do learn, but I make mistakes like everyone else. I’m bound to be far from the mark if I’m unsure about my information.

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I did similar research and found so many claims and so much evidence that 12/12 from seed works, that I wouldn’t hesitate to try it. I haven’t yet, but I certainly will at some point.

For your purposes, go with your gut and do a 2 week veg and then flip.

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It works and isn’t the worst way to pheno hunt in a bunch of 1 gallons…I personally don’t like it (my opinion means about zilch though so please take it with a grain of salt), and am in agreement with @OniTenshu about stress issues…it’s a fun endeavor and allows a different aspect of growing techniques to be learned, from a hobby stand point everyone should give it a try though just to say you did it once :smiley:

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Imo photo period won’t start to flower until there ready to do so from any information I’v gathered on the subject when 12/12 from seed I guess it kinda depends on how big of a harvest you want, my two ladies I have going now I started 12/12 from seedling for two weeks then gradually raised it to 18/6 over the next weeks seemed to do fine maybe that’s why I was able to determine very early in what the sex was.

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Clones will be ready in less time given that by the time you cut them they are prolly sexually mature. On the other hand, from seed they need a few internodes to start reaching mature age.

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Running 12/12 usually gives you those single cola plants… It’s not gonna cut the time of a photo as it still has to be mature enough to flower, just drastically reduces height and side branching

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Ya you can start 12/12 from seed or thereabouts, but you may not get a proper representation of the plants potential. I find plants always seem more vigorous, potent and yield better when I run then a second time from clone.

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It’s recommended for long-flowering sativas in some cases to cut down on height issues. From what I understand, limited as it is, the plant will decide when it’s ready. The natural equatorial lighting is 12 hours year-round. Then to finish, cut the light down to 11 on…
Happy growing. :slight_smile:

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i did 12/12 from seed once and it still took 8 weeks or more before i saw pistils … they won’t flower until they’re sexually mature i.e. preflowers

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I’ll just repeat what’s been said here. A seedling will veg for three of four weeks even on a 12/12 cycle. Once they are mature (showing pre-flowers or alternating nodes), they will start to flower under 12/12. I know you aren’t planning to go 12/12 from seed though.

Starting to flower too young can cause hormonal stress as the flowering hormones build up. Like any stress, this can potentially lead to intersex traits. Generally I like to go four weeks from sprout then flip.

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i have a few plants which i’ve been waiting for preflowers on, probably 4 weeks or more from sprout and they’re still in solo cups, then i have one thats prob over 8 weeks in a 1 or 2 L pot still hasn’t showed so i threw a bottom branch in to the flower tent in a cup of coco and its been 1-2 weeks and that hasnt done shit either yet!!

i had to cull 3 males from my flower tent and that’s pissing me off … i’m investing in a qPCR thermal cycler so i can do at-home sex testing of my plants … that’s it

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Right, of course…the good old qPCR thermal cycler. Gotta have one of those!!

Seriously though, what the hell is a qPCR thermal cycler lol

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I found whether 12/12 from start or not your plants are still gonna go through a veg cycle for that first 2.5-3weeks anyways before they think or even can consider flowering, and found it was more a benefit to just given them more light to start off with anyways.

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hehehehehe You folks are sounding just like the folks I found when I Googled this - all over the place!

So, to sum up, flipping early may work just fine or maybe not :smiley:

It sounds like the worst case is hermie city from stress, and/or stunted growth, smaller colas, etc. Plus, it may not actually reduce he grow time at all.

So, I need to balance that against the roots outgrowing the available space well before harvest, and the stress and other issues from that situation…

My current grow is still a week or so away from harvest, so Im starting the seeds for the next grow in dixie cups now. That will give them at least a week or two head start while I clean and make changes to the HPA system.

I really should have started them last week or even earlier now that I think on it…

I guess I will just have to see how it goes. I will report back!!

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quantitative polymerase chain reaction thermal cycler, it rapidly heats and cools a sample while spinning to separate and analyze the nucleic acids … in this application it looks for a Y chromosome to identify male samples

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Im waaay too broke to get one of those. I just buy fem seeds :slight_smile:

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I have a PCR I got from gov auction. I’ve wanted to start messing with it but I’m not sure where to buy chemicals without a business licence. Do you have any guides you’ve looked at?

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actual qualitative/real-time PCR isn’t absolutely necessary, it’s possible to do standard PCR detection and you could build a DIY arduino one for under $85

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