The Old Debate, Veg Room, 18/6 or 24 ?

[CANNACO-OP]

I did a search and thanks for all you have compiled some data out there. Thought would put a poll with this and get one thread that stays around for all the newbie's and for the experts to give us the juice on this topic:

We have done both and are okay with both, guess that is why posting this thread.

Currently we have been under 24, but leaning towards going to 18/6 and would like some help in the process.

We did some math and obviously 18/6 saves some cash, maybe even a significant amount depending on who and what ya doing. Also thinking 18/6 more natural for the plants and see the point of root developement occuring at night. We do have veg time and not flowering asap so think the 18/6 would help there also. Biggest fear is with 18/6 how necessiary is the complete darkness and will light leaks and/or interuptions create a problem that is not there under the 24 hour cycle. Also, we have come to do this currently, under the 24 hour cycle, they get at least 12 or 18 under full strength, but the other 12 or 6 (usually 6) the small flouro's are just running and not T-5 (we use T-5 for veg).

Thanks.

 

[MMAJAY]

18/6 allways done very well for me so in turn i can't see useing the extra electric. I allways stick with what works. I have no desire to try 24/0

 

[PrinSeshJasmine]

.

 

[ddrew]

I used to go 24, but switched to 18/6 last year, really didn't notice much difference in the plants, maybe a bit better, definitely not worse.
But I did see a nice drop in the power bill, so, if it's all the same to the plants, at least from what I can see, I'd rather save money and go 18/6, prolong your bulb life as well I would think.

 

[shaunmulok]

There is a thread around that shows a comparison done and 20/4 was the highest yielding crop with the same strain and nutes
So i vote 20/4

 

[Clackamas Coot]

I used to go 24, but switched to 18/6 last year, really didn't notice much difference in the plants, maybe a bit better, definitely not worse.

Exact same experience here.

It's definitely better to run 18/6 vs 24 during the summer months unless you've got a ton of money to burn trying to combat 105+ temperatures like we had this past week. Running 25% less veg time helped.

YMMV

CC

 

[shaunmulok]

here is what i found
Got this from somewhere - Think poster is ot1

Lighting Schedule

We did a lot of experiments with light times a few years back using known sativa and sativa dominant clone lines.

With Vegging under HID lights.

20/4 produced the sturdiest growth and the most bulk. Best final yield, taken as 100%
22/2 Less of both growth and bulk. Yield 88%
18/6 Sturdier than 22/2 but slightly less bulk. Yield 87%
24/0 Much lighter in all aspects than 18/6. Yield 79%
16/8 The weediest plants. Yield 67%

Plants vegged to final pots under fluorescents at 20w per sq ft on 18/6 yield 49%

Have not tried 36 hrs dark but did try 48 hrs from 18/6 veg. The final yield was down between 15% and 20% by varying the pure sativas
with the biggest loss in final weight and caused the odd herm, [sativas] it did reduce the flowering time by 5 to 8 days.

For the mum lines we have 20/4 to 12/12 gives the best crop weight and bud quality, really that’s all I’m interested in.

 

[Abja Roots]

During the summer 18/6 and during the winter 20/4

 

[shaunmulok]

Got this from somewhere - Think poster is ot1

Lighting Schedule

We did a lot of experiments with light times a few years back using known sativa and sativa dominant clone lines.

With Vegging under HID lights.

20/4 produced the sturdiest growth and the most bulk. Best final yield, taken as 100%
22/2 Less of both growth and bulk. Yield 88%
18/6 Sturdier than 22/2 but slightly less bulk. Yield 87%
24/0 Much lighter in all aspects than 18/6. Yield 79%
16/8 The weediest plants. Yield 67%

Plants vegged to final pots under fluorescents at 20w per sq ft on 18/6 yield 49%

Have not tried 36 hrs dark but did try 48 hrs from 18/6 veg. The final yield was down between 15% and 20% by varying the pure sativas
with the biggest loss in final weight and caused the odd herm, [sativas] it did reduce the flowering time by 5 to 8 days.

For the mum lines we have 20/4 to 12/12 gives the best crop weight and bud quality, really that’s all I’m interested in.

here is the original post i found sorry i couldn't edit

 

[Maj.PotHead]

here is the original post i found sorry i couldn't edit

GJ i was just gonna dig this up thx

 

[guest 77721]

My experience is that adjusting the light times is a good tool to pull out when you need it.

Healthy plants will grow at their maximum rate at 24/0. The stable temperature is good for winter vegging in a cool basement. Peak temperatures will be reached on hot summer days.

18/6 gives the plants a chance to grow roots as growth rate is reduced. Good choice for rooting clones and for recovering from deficiencies. Use to reduce high temps during summer.

 

[Greyskull]

24/0 is the way i roll
the girls can get some sleep when they get into flower... and then they'll get plenty of slepp.
until then, they need to work.

i like the growth rates of 24/0 as opposed to 18/6. MAYBE ITS MY ENVIRNMENT AND HOW I TREAT THEM but for me 6 hours of darkness equalls a few more days of veg growth.... but i grow perpetuallly and its been working for me for some time now.

 

[CANNACO-OP]

Looks like Canna should have done some research b4 posting,

can some1 or a moderator modify my poll to inclue the 20/4 option?


Thanks for the info so far, keep it coming, but looks like the 20/4 sounds appealing to me.

 

[KnuckleHedd]

Years ago I did 24/0 for a while. I have healthier plants going 18/6. I did 20/4 for quite a while. It's entirly strain dependant, of course, but 18 hours is about the point of diminishing returns. You'll get some more growth going 24, but not 33% as the numbers might suggest. My vegging plants are greener and more vigorous on 18 hours. I do use 24 hours when I take cuttings in the 3rd or 4th week of 12/12 in order for them to revert to veg.

 

[Mist]

I am with the 18/6 crowd. I have done 24 hour before and just don't see the need to push the plants that hard. There are many "studies" that say that cannabis doesn't need dark time to recover nutrients, transpire waste or grow roots. But after 30 years of growing I disagree with those studies and will stick to 18/6.
And I don't see where the vegg light cycle would effect the yield of the plant. I have done the same strain with 24 hour light and 18/6 before due to vegging in my mother area when I was out of space and saw no difference in yield at the end of flowering. The main difference was the internode distance in which the 18/6 plants were much more compact and bushy.
I DO keep my mother plants on 24 hour floro lights. This is to make sure that I get no preflowers starting on them. And I also want them to be a bit leggier for cuttings.

 

[Budley Doright]

I DO keep my mother plants on 24 hour floro lights. This is to make sure that I get no preflowers starting on them. And I also want them to be a bit leggier for cuttings.

I find the comment about no preflowers interesting....

I find that using 24-0 promotes autoflowering.....

That a cycle with a dark period is better at not producing flowers.....

Not all mind you.... but some plants dont like 24-0


Anyone else notice that????

 

[stihgnobevoli]

yes i noticed that.

reveg plant, cloned under 24/0 continued to grow preflowers. this is after 3 weeks 24/0.

i myself like 18/6 20/4 for veg when i veg. like someone said up there i know studies say that weed doesnt need to sleep, but i disagree. i find that plants grow faster when theres a dark period. ive tried all the variations from 24/0 on up . ive always gone back to 18/6. i think i might try 20/4 again the next run though.

 

[AzGrOw-N-sMoKe]

what i found threwout reading is studys saying that plants need some dark time each day....i cant think of the name off hand what the process is called...with knowing this i give my plants a dark time..an as someone posted earlier 18/6 summer 20/4 winter...but its also strain specfic as-well i've found that plants that were grown outdoors near the equator prefer a light cycle of 13/11veg 11/13 flower...but for the majority yea 18-20 hours light works well imo...peace az

 

[barnyard]

is it safe to run HID's 24/7?...

is it safe to run HID's 24/7?...

I thought HID's needed a cooling period and should not be run 24/7 b/c of over-heating issues

on the other hand, florescent bulbs can be run 24/7

I've always used a couple of florescent shop lights for veg on all the time and HID's for flowering

Cannabis does not need any dark period during veg stage

 

[THC farmer]

definately clines root better under 18/6 or 16/8 and i have too, noticed healthier vegging plantsunder 18/6 as opposed to 24/0