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

[One Puff]

So is there a definitive answer to this? What light application produces the highest quality buds? Is each strain different in the amount of light they like? If 12/12 produces the same quality buds as longer light periods as some in this post suggest may be time to change my thinking. No need to spend more money and give the plants more light than they need.

 

[miniclips320]

I've been wondering about this, myself. I'm only on my second grow (week 7) and, while I have played around with them and learned a lot, it's only now that I reconsidered my lighting hours. For my entire first grow I went 24/0, and the same so far on my current grow. I figured that since all the literature says autoflowers can go this high, I wouldn't sweat it, but now I wonder what a period of dark might do for them.

Can anybody point to a good source on this? Am I stressing my plants on 24/0? (They look good, except for some nute burn I'm remedying.) I think I'm on target for the estimated yields. They might be finishing a little early, as I've had a small number of amber trichomes (maybe 5% and not the same from plant to plant) developing for several days now. I'll probably chop down one or two right at the end of week 8, but I'd like to see how the rest develop with more time.

OR ... would there be any point in providing a dark period for the next week(s)?

So end of the day the roots really dont got much time too relax and grow and do its thing to send nutes how it should so i would always recommend that 4 hrs of darkness

 

[Srfr]

I've always had great results running 24/0 and it's particularly helpful in winter in the UK to help keep temps and humidity stable. In the summer, sometimes I'll turn the light's off during the hottest part of the day if temps are a problem. I think the key is the DLI. Rudy plants growing on the Russian steppe get 24 hours light during summer and I'd say are adapted for it. I don't think there is a definitive answer here, unless someone has done a proper side by side? I've not read all the replies...

 

[WildBill]

I've always had great results running 24/0 and it's particularly helpful in winter in the UK to help keep temps and humidity stable. In the summer, sometimes I'll turn the light's off during the hottest part of the day if temps are a problem. I think the key is the DLI. Rudy plants growing on the Russian steppe get 24 hours light during summer and I'd say are adapted for it. I don't think there is a definitive answer here, unless someone has done a proper side by side? I've not read all the replies...

I've used 24/0 quite often, but only one grow full cycle. Like you, I've used it mainly in the early life stage to maintain heat in the winter time, but I normally don't do that for long. I just did not like the quality of the buds when I ran them 24/0 .
I think my next auto run they will be 20/4. By then I should have my CO2 running sorted out and that should prove interesting.

 

[Srfr]

I've used 24/0 quite often, but only one grow full cycle. Like you, I've used it mainly in the early life stage to maintain heat in the winter time, but I normally don't do that for long. I just did not like the quality of the buds when I ran them 24/0 .
I think my next auto run they will be 20/4. By then I should have my CO2 running sorted out and that should prove interesting.

I might give 20/4 a go in the summer and see if I can detect any difference.

 

[WildBill]

I might give 20/4 a go in the summer and see if I can detect any difference.

I think the plant needs a rest period, especially the root system and the microbes along with it.
I think it matters especially for organics but it does come into play with chemical. That's my interpretation and thought process.
With the proper light for the space, it's very easy to hit the proper DLI for an auto and not have to go to a 24/0 light schedule.

I'm trying to wrap my head around this upcoming grow. The biggest thing is to maintain my quality of buds with less time in light exposure by growing photos indoors. I will have to hit them harder when in flower then I normally do with autos. Less time to meet the DLI means a higher ppfd.

I'm gonna buffer that a little bit in this next grow by introducing CO2. Now I'm not introducing CO2 maximize production, only to slightly enhance and to be assured of the proper level available to them.

Ever since changing AC systems and having a more sealed grow room, I've kind of suspected some of my CO2 levels have been borderline. Now since I'm totally organic and living soil, my tent CO2 levels are going to be significantly higher than someone in a hydroponic or chemical grow.
I got my AC Infinity CO2 controller in at the end of the past grow. I think I only had two plants left. I monitored the CO2 levels in the grow room and most of the time they were at ambient levels. Now that kind of has me a bit concerned. What would the levels be with all 3 tents filled with girls raging hard? I think logic would ensue that it would be lower overall. Now granted, there would be more biological activity in the pots, but that don't think it would make up the difference.

I've already had one successful photo grow. I stonered out and forgot that I had asked For photos on this test run.

When the two girls still weren't flowering with every other one in the grow well into flower, I went back to my seed stash and looked closely.

So I kind of had to play musical cannabis plants to get them in a tent to themselves.
Both girls perform extremely nicely, but I feel I could have done a bit better.

In the end, if your environmental and lighting conditions are met properly, I think you'll see an improvement in many ways, but mainly the quality of your buds.

 

[Srfr]

I think the plant needs a rest period, especially the root system and the microbes along with it.
I think it matters especially for organics but it does come into play with chemical. That's my interpretation and thought process.
With the proper light for the space, it's very easy to hit the proper DLI for an auto and not have to go to a 24/0 light schedule.

I'm trying to wrap my head around this upcoming grow. The biggest thing is to maintain my quality of buds with less time in light exposure by growing photos indoors. I will have to hit them harder when in flower then I normally do with autos. Less time to meet the DLI means a higher ppfd.

I'm gonna buffer that a little bit in this next grow by introducing CO2. Now I'm not introducing CO2 maximize production, only to slightly enhance and to be assured of the proper level available to them.

Ever since changing AC systems and having a more sealed grow room, I've kind of suspected some of my CO2 levels have been borderline. Now since I'm totally organic and living soil, my tent CO2 levels are going to be significantly higher than someone in a hydroponic or chemical grow.
I got my AC Infinity CO2 controller in at the end of the past grow. I think I only had two plants left. I monitored the CO2 levels in the grow room and most of the time they were at ambient levels. Now that kind of has me a bit concerned. What would the levels be with all 3 tents filled with girls raging hard? I think logic would ensue that it would be lower overall. Now granted, there would be more biological activity in the pots, but that don't think it would make up the difference.

I've already had one successful photo grow. I stonered out and forgot that I had asked For photos on this test run.

When the two girls still weren't flowering with every other one in the grow well into flower, I went back to my seed stash and looked closely.

So I kind of had to play musical cannabis plants to get them in a tent to themselves.
Both girls perform extremely nicely, but I feel I could have done a bit better.

In the end, if your environmental and lighting conditions are met properly, I think you'll see an improvement in many ways, but mainly the quality of your buds.

I've read so much on this topic and I'm still not convinced 24 hours is problematic. As I said Ruderalis growing in the wild in the middle of summer gets 24 hours of light and that's what they have evolved to deal with. Sure, modern autos have reg DNA too but I've just not been convinced about this rest period. Each to their own (and most of us find a method that works and we stick to it, me included), but I do find running 24-hour light in winter is very beneficial with temps and stable humidity. In summer, as I said, I do often have a dark period in the hottest part of the day to help control temps but I increase the intensity of my LED to keep the DLI in the right range. I personally have not noticed a difference in quality.
Whatever works for you I guess! I'll try and pay more attention this summer and see if I can detect any difference. Maybe more stretch due to darkness helps open things up more and helps with bud structure?