12/12 vs 18/6 ... DLI vs Yield

[OregonBlackBear]

I have grown autos the exact same soil/tent/temps/environment with the only variable being light schedule and I had diminished results at 12/12 vs 18/6 or 20/4. Every. Single. Time.

I'd love to read someone's grow and show on it, but my mind is very firm after years of the same result.

 

[Simplicio]

Daily Light Integral leaves out important information.
400 kLux for 1 hr, and 20 kLux for 20 hours have the same DLI, assuming identical spectra.
These are extremes, but point out the fact that different light levels might affect plant health differently.

My own experience is that my autos don't like as much light as is commonly recommended.

 

[KodakB]

I have grown autos the exact same soil/tent/temps/environment with the only variable being light schedule and I had diminished results at 12/12 vs 18/6 or 20/4. Every. Single. Time.

I'd love to read someone's grow and show on it, but my mind is very firm after years of the same result.

But did u adjusted the PPFD's for the 12/12? aka did you used more wattage ? Or did you had your lights at closer distance?

 

[KodakB]

Daily Light Integral leaves out important information.
400 kLux for 1 hr, and 20 kLux for 20 hours have the same DLI, assuming identical spectra.
These are extremes, but point out the fact that different light levels might affect plant health differently.

My own experience is that my autos don't like as much light as is commonly recommended.

Sure, but 400k lux is around 9000 ppfd and the maximum amount of ppfd you can give to cannabis is ~1500.

 

[OregonBlackBear]

But did u adjusted the PPFD's for the 12/12? aka did you used more wattage ? Or did you had your lights at closer distance?

No. As I said everything was the same except for the light schedule. Lowering your light or adding more wattage does not mean you get more or the same from 12/12, it means you're exposing them to stronger light. You can hypothesize all you want, but the lived experience of many growers over the years on this site is 12/12 is reduced results vs longer daily light exposure for autos. Many actual grows here and on other sites have replicated this result.

Until you show me this in a grow with a proper sample group and control these hypotheses carry no actual weight. This is especially true considering the mountains of evidence to the contrary.

 

[KodakB]

No. As I said everything was the same except for the light schedule. Lowering your light or adding more wattage does not mean you get more or the same from 12/12, it means you're exposing them to stronger light. You can hypothesize all you want, but the lived experience of many growers over the years on this site is 12/12 is reduced results vs longer daily light exposure for autos. Many actual grows here and on other sites have replicated this result.

Until you show me this in a grow with a proper sample group and control these hypotheses carry no actual weight. This is especially true considering the mountains of evidence to the contrary.

well yes but if ppfd wasnt adjusted accordingly, that experience is invalid to my hypothesize...

The entire point is raising light intensity to make up for 12/12 and keep the same DLI. To test this you would need a high quality luxmeter..

 

[Death The Cultivator]

well yes but if ppfd wasnt adjusted accordingly, that experience is invalid to my hypothesize...

The entire point is raising light intensity to make up for 12/12 and keep the same DLI. To test this you would need a high quality luxmeter..

An apogee Epar would work in a well controlled environment but I imagine you would need a large amount of plants to have validity.

 

[derek420colorado]

well yes but if ppfd wasnt adjusted accordingly, that experience is invalid to my hypothesize...

The entire point is raising light intensity to make up for 12/12 and keep the same DLI. To test this you would need a high quality luxmeter..

I got one, but I don’t run photos and need to run my lights all night for the heat. So I would t be of much help. But I would like to see someone try this out. In theory it should work right

 

[OregonBlackBear]

well yes but if ppfd wasnt adjusted accordingly, that experience is invalid to my hypothesize...

The entire point is raising light intensity to make up for 12/12 and keep the same DLI. To test this you would need a high quality luxmeter..

No, i've been following just fine from the start. If you adjust your lights to give more intensity to the plants by lowering your light or raising intensity you are not getting the same from a 12/12 as you are an 18/6. You are adjusting the environment (lights) between the two to make up for the lack of hours in 12/12. Use that same setting for both 12/12 and 18/6 and the 18/6 schedule will out yield the 12/12.

 

[KodakB]

No, i've been following just fine from the start. If you adjust your lights to give more intensity to the plants by lowering your light or raising intensity you are not getting the same from a 12/12 as you are an 18/6. You are adjusting the environment (lights) between the two to make up for the lack of hours in 12/12. Use that same setting for both 12/12 and 18/6 and the 18/6 schedule will out yield the 12/12.

Yes, if you use the same setting for both, the 18/6 will have higher DLI ence higher yield. That is not in dispute.

What im saying is that you could also achieve an ideal DLI (60) with only 12 hours, by running at ~1300 ppfd. And that in theory would out-yield 18/6 at 625ppfd.