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18 hour light cycle

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Here in the not too distant past (I'm a stoner that works nights, my sense of days is all screwed up, so I can't do any better on timing), there was a post about 18 hour light cycles.

Now, from what I remember, I want to say it was posted on OG, quoting a write up over here by IMBoggled, where IM was referencing an article from a non-cannabis focused hydro site.

The article discussed a growers experiments with 18 hour light cycles, based on the theory that plants were most effecient at gathering light during only a portion of the 'day' cycle. I want to say that during veg, he used 14 on 6 off, and during flower he used 6 on 12 off.

The grower claimed a 3 week shorter harvest cycle, with a 30-40% increase in yield.

Something about this rang true to me, and I want to reread the article, anyone know what I'm talking about or where to find more info? I've tried google, and of course the respective search functions on each site I frequent, with no luck.

With recent events, I find myself with a spare 1k light, and, shortly, plenty of space. I was going to do a side by side with one 1k running a standard cycle, and the other running the 18 hour cycle, see if there's any reproducability of the claimed results.

Can anyone else remember this article?
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Yeah, after some thought and number crunching, I wanted to reread it, but now I've lost the post LOL

I think at the very least it's worth the experiment. The idea of getting 30% more harvest in three weeks less time should peak the interest of any cannabis grower :)

*goes back to daydreaming about a 5 week 2 pound harvest*

:D
 

Verite

My little pony.. my little pony
Veteran
The 30-40% yield increase is hermie seeds and the 3 weeks shorter is from despair rather than maturity.
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
What makes you say this Verite? Have you seen the article?

I'm curious if I missed something (that's why I want to reread the article :)), but why do you think there were (or would be) hermies?
 
G

Guest

i think i know what your talking about.... was it an article posted on OG? might be able to find it
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Yeah, like I mentioned, I think it was posted OG, but I thought it was by IMBoggled over here, and the OG post quoted it.

You don't have a link by chance do you?
 
G

Guest

Majority of people have no idea what you're talking about.

But i know. You're talking about the shit that after 4 hours of light the photosyntesis process almost halts, and giving the plant at least 3 hours darkness to use the energy.

Yeah, in theory you could use it to speed up the plants' growing processes. I would only use it in veg though, and still go 12/12 in flower.

I'd use 6/6 in veg. So 2 cycles in a day..

-v1
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Yeah Virus, that was basically this guys gist, but he didn't knock it down quite that dramatically. Basically, the way it read, during flower, the plants got 6 hours of light, and 12 hours dark.

Basically, the gist I got was he was playing to the plants metabolism. Plants need thier 12 hours of dark, it's how they know to flower, so that doesn't get messed with. However, they didn't need 12 hrs per light, they only used about 6, so that's what he gave them.

So the plants got 60 days worth of dark cycles in less time. It has a wierd symmetry in my mind that makes me want to investigate further and run the experiment.

Do you have a link Virus?
 

Verite

My little pony.. my little pony
Veteran
Imo youre applying something highly unnatural to something that expects something consistantly different. Whats the normal outcome of messing with weeds photoperiod, hermies, no? Im also at a loss to figure how reducing the on photoperiod by 50% would be able to increase yields.
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Ah, I get you, your commenting on the methods, I thought you read the article and caught something I'd missed :)

The idea, from what I remember, is that hermie's would not be a problem since you are not interrupting or tampering with the 12 hour dark cycle. You're not stressing the plant because the theory is that the plant only uses about 4 hours of the light it recieves.

As far as the increased yeild, I'm not sure what would cause that, and until reproduced, I agree it's a highly speculative claim. The only thing I could think of that might affect the yeild would be effeciency? The plant is more effecient using the energy it recieves when it gets all that it needs, and then immediately has a dark period to use it?

It makes enough sense to try the experiment, I think.
 

Bucket Boy

Member
Nite Tiger

Nite Tiger

I read an article in High Times about 6 months ago about staggering the lights, and experimenting with the light cycles. Exactly what your saying about the increased yields, less power consumption etc. I will look at home tonight and get you the exact month..
 
G

Guest

I run 18/6 for one reason: pre-flowering. When my plants are on 18/6 they reach pre-flower much faster than my plants grown under 24/0. 24/0 will extend your bulb life though probably. I also agree in that I notice clones flowered after 18/6 tend to mature a little faster. Just my experiance though. In addition, my clones under 24/0 don't seem to show any more or that much vigor than the ones under 18/6. It seems each person you talk to though has a totally different opinion though. my 2cents
 

Rattrap

Member
Very interesting night tiger, i wish i could add to this but i'm in the dark about it too. I just follow the usual 18/6 & 12/12 rule but then i'm always looking for an excuse to break rules. hehe I'll be keeping an eye open for more info on this subject, good luck!
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
disciplinedjinn said:
I run 18/6 for one reason: pre-flowering. When my plants are on 18/6 they reach pre-flower much faster than my plants grown under 24/0. 24/0 will extend your bulb life though probably. I also agree in that I notice clones flowered after 18/6 tend to mature a little faster. Just my experiance though. In addition, my clones under 24/0 don't seem to show any more or that much vigor than the ones under 18/6. It seems each person you talk to though has a totally different opinion though. my 2cents

I'm guessing you misunderstood what I was referring to when I said '18 hour light cycle'. I'm not referring to 18/6, which is a 24 hour cycle. The equivalent of 18/6 in an 18 hour cycle would be 12/6. Hope that clears up any confusion.

Rattrap, yeah, I think it's interesting enough to explore further. Since I've got the time, the equipment, and the interest, I guess I'll give it a shot when I get the new room set up. It'll be interesting, to say the least.
 

Nuggy

Member
He's talking about an 18 hour light cycle like the Harvest Master has. it's 6 hours of light 12 hours dark for flowering, and 14 hours light 4 hours dark for vegging. You get about 2 more light cycles a week.

For those of you still confused, they are 18 hour days, not 24 hour days. That's about as simple as I can put it. If you still don't understand go play in traffic
 

NiteTiger

Tiger, Tiger, burning bright...
Veteran
Thanks for the help Nuggy!

Do you have a link to Harvest Master grows or threads where he discusses his light cycles?
 
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