Seedlings, Clones, Need Night?

Do you need or is it helpful to have a dark periond like 18/6 for seedlings? Do clones have the same needs? Or is 24/7 the way to go? If you know please explain . Thank you.

Hello? Anyone know the answer to the question??

I belive its 24/7 until they root

tonyromo said:

Hello? Anyone know the answer to the question??

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I personally don't think you should do a 24h lighting period, i think the plants nee at least 2 hours of darkness to rest... but during veg, 24h light can be very good for the plants, they eat that shit up.
i would say, give the 18/6 until they start getting the second pair of leaves, then you can either do 22/2 or just a full 24.

Clones are growing plants though, they need lots of light, so you can do 20/4 or 24h
but that's just what i do

oh and if they haven't even sprouted yet, then 24h lighting isn't going to make them sprout that much faster.

Thanks I have heard a few opinions but read a couple sort of contradictory things reagarding this. I still am unclear what is the fastest growth method? To be clear the seedlings are about 4 inches tall and have around 10 leaves each, some are a bit smaller and the two clones are from bag seed plants that have been in flower for over 5 weeks so trying to keep those genes. Thanks... Need more help everyone so chime in if you have good info...

Need more answers to this question. Don't think that I got a right answer yet.

tonyromo said:

Thanks I have heard a few opinions but read a couple sort of contradictory things reagarding this. I still am unclear what is the fastest growth method? To be clear the seedlings are about 4 inches tall and have around 10 leaves each, some are a bit smaller and the two clones are from bag seed plants that have been in flower for over 5 weeks so trying to keep those genes. Thanks... Need more help everyone so chime in if you have good info...

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You are going to read contradictory things regarding everything you ask a question of here. The best thing I can recommend is to read, research and decide what might be best for your situation. If that doesn't work, try another way.

That's what makes this place great. With virtually millions of years of combined growing experience, you're bound to get conflicting opinions. While you ask a question about lighting, there are so many more variables to consider. What kind of soil, lights, temperature, humidity and so on.

I'm a noob here but I think the questions you ask are impossible to answer even by the most knowledgable grower. Sorry that I couldn't be of more help.

they need rest, i've been to a few boards and this is what the pros say, i've seen em duke it out over this, but it seems rest always wins

def. in a nutshell tho, research make up your own mind, peace

tonyromo said:

Do you need or is it helpful to have a dark periond like 18/6 for seedlings? Do clones have the same needs? Or is 24/7 the way to go? If you know please explain . Thank you.

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I do 24 hours of light for both so you can get your seedlings into veg ASAP and to get clones well rooted and on their way to veg. but, ide only use cfl's for cloneing till the roots become well established because the hot lights could possibly cook your roots. cfls are very cool. But once your plants move into veg ide switch to 18/6 then 12/12 for flowering.

tonyromo said:

Do you need or is it helpful to have a dark periond like 18/6 for seedlings? Do clones have the same needs? Or is 24/7 the way to go? If you know please explain . Thank you.

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Plants grow more efficiently during hours of darkness. When under light they are multitasking and the light energy absorbed is used for multiple purposes and not all for growing so in a 24/0 light cycle you do get 24 hours of light but the plants are not using all the light energy they absorb for growth.

During periods of darkness they ‘run’ off of stored energy and they shut down other functions and almost all energy is used for plant growth.

Have you never heard someone say, I swear, I looked at my plants this morning and I could tell they grew overnight? I have said it and I have known many people to say it and that is because plants use their stored/night energy more efficiently for growth than they do the energy that is being absorbed during the hours of light.

18/6 is better than 24/0.

18/6 is the way to go, then 12/12.

Brick Top said:

Plants grow more efficiently during hours of darkness. When under light they are multitasking and the light energy absorbed is used for multiple purposes and not all for growing so in a 24/0 light cycle you do get 24 hours of light but the plants are not using all the light energy they absorb for growth.

During periods of darkness they ‘run’ off of stored energy and they shut down other functions and almost all energy is used for plant growth.

Have you never heard someone say, I swear, I looked at my plants this morning and I could tell they grew overnight? I have said it and I have known many people to say it and that is because plants use their stored/night energy more efficiently for growth than they do the energy that is being absorbed during the hours of light.

18/6 is better than 24/0.

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Sorry but I beg to differ. I had my small (Less than 6") clones grow to 26" in about 3 weeks with 24/7 lighting. I'm using hydro too so that helped.
The plant will rest when it needs to, even with the lights on. just watch time lapse videos and you can see the plants rest and grow.
Plants need light to make food and grow so if you want the best growth you have to go 24/7. All the dark period does is trigger hormones that tell the plant to reproduce.

For me, I tend to experiment with different strains. I have had some that grow fastest under 20 / 4 and some under 18/6. When I started out, I used to veg for 24hrs but stopped once I realized there wasn't enough of a difference to justify running the light for 24hrs...

I would say go 20/4 or or 18/6 and save some money

i use 24/0 for veg on seedlings or clones to give 18 inches of tight node space then right to 12/12. my preference try out both see what works for you

Id give your plant at least two hours as well.
although i use 18/6 two hours should work fine.


when the lights are off the plant stops absorbing from above ground and starts using its roots

the roots will expand more in dark periods allowing it to gather more nutrients from the area around it.

Now that is what I call good answers. I still have not gotten the difinitive answer but I like the save money idea if no real difference will be obtained between 24/7 and 20,4/7. My seedlings are doing great but think after only 12 days and such outstanding growth, plants are 6 inchs and lots of fat tight noded leaves, that 24/7 is got my vote as of now. They are in a 350 ppm stacked rufneck with Bonicare Pro for nute. Lots of gunk with this nute but seems to work well. Want to use a synthetic/chemical nute but no one will say what is a decent one with hydro. Like Jacks Classic or one that is not 1 million dollars, LOL. As for roots you could not want more root growth than I have on 24/7 lights. They are 15 inches long so had to put the tub on another and let the water pump up from the lower one so the roots were not in the water all the time. Have the cycle for water coming on 15mis and off 30 seems good? Thanks for more info and gl...

Savedbythesmell said:

Id give your plant at least two hours as well.
although i use 18/6 two hours should work fine.


when the lights are off the plant stops absorbing from above ground and starts using its roots

the roots will expand more in dark periods allowing it to gather more nutrients from the area around it.

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I think that the plants grow just has much with the lights out has long has you are giveing them 18 hours thats fine.Not only that is a lot better on the electrical equipment that you are useing.I compared grow notes that i have took and the cooling of period does not mean the gain that much extra by haveing your lights on a extra 6 hours.I would only do the 24 thing if i was in a rush that extra 6 hours a night is not stopping you plants from growing i have marked one set of plants on 24/7 and 1 set on 18/6 the differance was only just over 1 and harf ince.