Lighting What's the best lighting cycle for autos - 24/0, 20/4 or 18/6

[geddy]

depends on lights used , i run a blackdog led and 400 watt hortilux in together also 4 bank t5 , biggest cola auto ultimate ,dp. depends on pot size also,i like the big airpots, with very light soil mix.. oppsthat cola was 18 inchs,seen bigger but im happy..

 

[Creekerboy81]

I just do 18/6 with mine and they seem to be doing fine. Not sure of time but I did notice today the white hairs just popped so I switched to HPS and prob leave same light schedule..they are midway thru 3rd week

 

[puggle6]

I have a day 4 girl under T5, currently 24/7 dwc in my fish tank.

was thinking 20/4 but my temps and everything is running great, any thoughts?

aquaponics but treat as hydro Hehe

 

[doobydoobydo]

i do 20/4 but with the price of electricity i may go to 18/6

 

[heathcliff]

I asked mitch@mephistogenetics.com and he says that running them 24-0 is OK, 20_4 makes them real healthy and 18-6 makes them finish faster. They have done thousands of grows.

 

[Nash]

Euh...

24/0 means 24 (light) + 0 (darkness) = 24 hours
20/4 means 20 (light) + 4 (darkness) = 24 hours
18/6 means 18 (light) + 6 (darkness) = 24 hours

Hummm...

Why should an "auto" conform to a 24 hours schedule exactly???

After all, i'm ready to bet there's some excess time wasted here!

How many hours does a plant need to rest? How many hours can she work before she needs to rest?... What's a cannabis plant supposed to do when it's not time for her to be resting nor working!??

Is this all just because there ain't no timers on the market which would support days with a different duration than our terrestrial day?

I wonder.

You can get them they are lighting event timer. You can run 18 hour days or 20 hour days or whatever. I read somewhere that after 8hours production starts to slow I think. Gaining 4hours a day could be handy lol


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[Sensyganja420]

Hello everybody,

The overall yield in autos depends on root mass and and the plant size as well. Knowing that, you can give them 18/6 of lights until 4-6 weeks after germination to make sure it get the biggest root mass and structure that it can. Then you can cut back the light to 12/12 if you wanna save on the bills. Yields are a bit lower but I bet running this technique properly in dwc could work.
I tried this method with pineapple express auto from barney's farm. Unfortunately the grow room was overcrowded and I used small volume smartpots in coco. But still, the plants grew up to 3' if I remember. With better light penetration.
Here's a pic of the plant that finally yielded 16g dry weight. You can see the yield potential.

I still have to experiment with this method when I have time. But the yields aren't really less according to my intuition after this experiment.

Cheers

 

[derek420colorado]

24/0 autos are influenced by their rudy genes, which virtually all autoflowering cannabis comes from the northern most latitudes where they have short summers of virtually 24 hours of light. So what happens in nature is what they have adapated to thrive in, by cutting their natural light cycle down to 18/6 is inhibiting the plants ability to reach its maximum genetic potential. Some plants do need a rest period, autoflowering cannabis is not one of them IMO. And @Sensyganja420 you are 1000000% correct yield is directly related root mass, just for shites and giggles here is a picture of the roots of my autoxtreme

where 6 plants yielded 1800 grams and 3 of the 6 were over a pound a piece. This was done on a light cycle of 24/0 from start to finish. Now I DO understand some have power concerns or temp problems etc and those are definitely instances where cutting the light cycle may be 100 % necessary but to get the biggest plants you will want to go with 0 hours of dark

 

[SHRED]

24/0 autos are influenced by their rudy genes, which virtually all autoflowering cannabis comes from the northern most latitudes where they have short summers of virtually 24 hours of light. So what happens in nature is what they have adapated to thrive in, by cutting their natural light cycle down to 18/6 is inhibiting the plants ability to reach its maximum genetic potential. Some plants do need a rest period, autoflowering cannabis is not one of them IMO. And @Sensyganja420 you are 1000000% correct yield is directly related root mass, just for shites and giggles here is a picture of the roots of my autoxtreme View attachment 638943 where 6 plants yielded 1800 grams and 3 of the 6 were over a pound a piece. This was done on a light cycle of 24/0 from start to finish. Now I DO understand some have power concerns or temp problems etc and those are definitely instances where cutting the light cycle may be 100 % necessary but to get the biggest plants you will want to go with 0 hours of dark

I'm one of those with energy bill concerns living in a very high rate zone.
I'm debating wether to run my T5HO lights at 24/0 for the first 3 weeks or so and then switch to my 315 LEC on either a 20/4 or 18/6 for the rest of the way.

 

[Sensyganja420]

@derek420colorado I might agree with you about 24/0 originally. But autoflowering have come a long way and are now further bred. I've grown 3rd generation autos. Basically ruderalis crossed with something else. Yield was good but doesn't even compare to 5th or 6th generation auto. Now how much ruderalis do u think there is in this generation ? (I have no idea, that's why i'm asking you). Breeders that want autos to big yield are breeding the strains to enlarge the vegetative period of this plant (over the years from 2-3 weeks to 4-5 even 6 weeks). Why does it work, cause the plant gets bigger.
Now we can speculate about the automatic gene. Ruderalis doesn't bring only the automatic gene, it also brings all the other genes it contains. Now if we could isolate the automatic gene just to keep it (what I think breeders are now trying to do to increase yield, potency and taste), that would mean that the new auto created is really different from the ruderalis found in nature up north.

All these are just speculation of course, but informations on autos are just kind of hard to find. Have we correctly understood yet how the automatic process works ?
I'm not saying you're wrong cause your theory makes a lot of sense (and will surely yield better) but so many protocols could be experimented in order to validate it.

Your roots looks awesome btw, what strains are you growing and how much power was used ? I don't even have to see your plant to know it's huge thanks to ur root mass. I've seen people bash on autos about small yields for the past few years. Funny thing is they always used a low volume of medium which reduced the root mass. I was truly impressed once I put em in bigger pots or DWC.

Thanks for answering, wish u the best