24 hour veg lighting vs 18 hour lighting...AND....GO!!!

[JKash]

So I've always done a 24 hour veg light... I feel it gives me comfort in 0% chance of a "pre-flower" and with the extra 6 hours they grow a little faster... other than running up power a little more this is MY preferred method...


So I wanna know do you do 18 or 24 hour light?

 

[trustyagut]

First run 18/6 for me

 

[BB22]

Super noob here. I’ve had a couple successful runs, always 18/6 veg 12/12 flower. Curious how this works out. Thanks.

 

[HerbalEdu]

plant metabolism change at night, so that's not not a so good idea to deprivate plant from night time even if they will still grow.

Understanding the Circadian Rhythms in Cannabis Plants

Let’s light up a discussion about how circadian rhythms in cannabis truly work & how to get the best harvest possible.

sensiseeds.com

"Research has clearly indicated that when plants are grown in conditions that deviate from the natural cycles of the habitat they’re adapted to, they suffer in terms of health, productivity and reproductive fitness.

A study published in 2005 compared mutant Arabidopsis thaliana plants that expressed abnormal circadian rhythms with normal wild-type specimens. It found that plants with circadian rhythms matched to their environments produced more chlorophyll, grew more rapidly, sequestered larger amounts of carbon, and generally survived better than plants whose circadian rhythms didn’t match their environment."

 

[Mikedin]

18/6 in veg, plants like a little siesta

 

[JKash]

18/6 in veg, plants like a little siesta

Plants in 24 hour veg

 

[JKash]

Super noob here. I’ve had a couple successful runs, always 18/6 veg 12/12 flower. Curious how this works out. Thanks.

I posted my 24 hour veg picture

 

[TLOnewbie]

18/6 for me
The plants need darkness for root development and to move sugars around to where they are needed
But
There are several ways to get where we are going

 

[ArtfulCodger]

I run 24/0 in my seedling area with a 2-foot T5. After three or four weeks, I move them to my veg tent under 18/6 until they're ready to flower. I don't have a scientific rationale for doing it this way, but it's always worked well. It's just the way the guy I learned from does it.

 

[LoveGrowingIt]

I've only used 18/6 till it's time to flower.

The conclusion I've seen most often is that eventually increasing the light time becomes a waste of electricity. We know plants can survive 24/0, probably because they're very adaptable. So, I think a question could be how much is gained when lighting is extended beyond 18 to 20 hours. Another question is whether there is any benefit in depriving plants of darkness.

When I monitor the CO2 levels in my tent or lung room, I can see that the CO2 level increases during dark periods and peaks about the time the lights come on. That's because at night the conversion of CO2 into food (photosynthesis) stops. Instead, plants take in oxygen and release carbon dioxide (respiration). It is believed that respiration is essential for plants to create the energy they need to fuel their growth. During respiration, plants break down the glucose they create during photosynthesis to release energy. Plants also use respiration to produce the compounds they need for growth, including amino acids, lipids and nucleotides.

I got most of this information here: How Many Hours of Dark Do Plants Typically Need? It's worth the time it takes to read it.

 

[AZreefer]

I run 24/0 in my seedling area with a 2-foot T5. After three or four weeks, I move them to my veg tent under 18/6 until they're ready to flower. I don't have a scientific rationale for doing it this way, but it's always worked well. It's just the way the guy I learned from does it.

Ty sir! I have been running my light 24 while i had babies. Been 2 weeks now and i was thinking i should switch to a 18/6 for veg. I was trying to keep temps stable for the sprouts and prevent temp swings. Now that the babies is girls i think a rest is in order.

 

[RootFarmer]

plant metabolism change at night, so that's not not a so good idea to deprivate plant from night time even if they will still grow.

Understanding the Circadian Rhythms in Cannabis Plants

Let’s light up a discussion about how circadian rhythms in cannabis truly work & how to get the best harvest possible.

sensiseeds.com

"Research has clearly indicated that when plants are grown in conditions that deviate from the natural cycles of the habitat they’re adapted to, they suffer in terms of health, productivity and reproductive fitness.

A study published in 2005 compared mutant Arabidopsis thaliana plants that expressed abnormal circadian rhythms with normal wild-type specimens. It found that plants with circadian rhythms matched to their environments produced more chlorophyll, grew more rapidly, sequestered larger amounts of carbon, and generally survived better than plants whose circadian rhythms didn’t match their environment."

Yep important things happen in the dark. The general day and night rhythm in plants is green (Photosynthesis) then grow (using energy stored during the day). At least how I approach it. I use a different strategy for seeds and clones. Clones are from a mature plant so it gets18/12, regardless. Seedlings I keep under 24 hrs until I get 3 sets of true leaves. Idk if it's just me but if I didn't I had a high chance of wilting. I've experimented with all kinds of light time combinations. What I do now works for me.

I initially estimate root size by leaf size and number of leaves rather than canopy reach like older plants. Height was something I considered at one time also but since I started using 6500k lights the extra blue keeps the internode spacing tighter and I seem to get more plant growth in less vertical space. I want to grow roots a solar panels quickly. When leaves start orienting upward toward the light nicely it's a good indication that roots are gaining momentum so they get stepped down to 18/12 over course of about a week.

 

[ccoki]

I have and am trying to move away from a 24hour veg room because of my hectic schedule. In the most simplistic way I can describe it....they become exhausted in a dailed in environment.

Not just cannabis though. I've been monitoring what 24hours does to other types of plants too.

I think it's the intensity of the light over duration of time. I've also noticed for the sake of the worms, and things occuring in the soil especially if you amend, a dark period is a good idea.

usually around that point they are transplanted and shuffled into the bloom room and put under 18/6 for a couple weeks where they happily perk up and start adding some height, then switch 12/12. Due to the environment change Im thinking of all the ways to reduce stress and what worked better in the past and I'm stopping 24hrs.

 

[Sunin]

18/6
rest is abuse

 

[802growz]

If you can make your dli at 18 hrs what would the point be in going 24 , I understand while cloning I run 24 but it’s a clone light , plants need to rest crucial processes happen . Hey and maybe you can save a bit of coin power isn’t cheap

 

[closettrapper217]

I ran 24 hours veg for my first few grows now I run 18-6 and it’s better hands down. I thought I was beating the game. There is a reason commercial grows that have unlimited resources don’t veg for 24 hours.

Plants respirate at a higher rate when photosynthesis ceases.

 

[closettrapper217]

At least try 20-4 and I guarantee you’ll see a positive difference.

 

[HerbalEdu]

really the only reason i would run 24h is if it was too cold and i need the heat from the light 24/24

if i remember mikedin shared a timelapse video with day and night where you clearly see plants had a growth rate boost at night when consuming sugar accumulated during the day.

 

[Ninjadogma]

really the only reason i would run 24h is if it was too cold and i need the heat from the light 24/24

if i remember mikedin shared a timelapse video with day and night where you clearly see plants had a growth rate boost at night when consuming sugar accumulated during the day.

I was kind of playing around with a 22 hour schedule through winter, combination of sun and artificial. They didn't really like it, my tops were swirling like pinwheels... But they got super dense. I can't say if that (slow but dense growth) was from the long light or the cold roots through a So Cal winter, but I'm looking forward to seeing how it turns out. Well, one bushy little beast in particular.

 

[figolus]

i dont know ,i dont use veg time , i am Always under 11/13 from seed