Dumb light question?

The following questions are for Auto Flowers.

Can too high of a PPFD, Such as 770 over a 14 day old plant Slow the growth?

Like it makes sense that too little light would slow growth, but can to much light also slow growth?

What’s that light schedule? 12/12, 18/6, 24/0? 770 you would want close to 12/12, it would be to much for a veg light cycle such as 18/6

I usually aim for about 350-400 par when they're 14 days old. Some strains don't mind more light and some strains want you to take it easy.
You will have to watch your plant, see how it reacts, then adjust accordingly.

IndooorGardnerOhio said:

The following questions are for Auto Flowers.

Can too high of a PPFD, Such as 770 over a 14 day old plant Slow the growth?

Like it makes sense that too little light would slow growth, but can to much light also slow growth?

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[edit]

Apologies - I misread the fact that it's a 14 day old plant. I get my plants to the light saturation point as soon as possible but, at 14 days, my plants have been in the 400-450µmol range, running 24/0 with DLI's in the mid-20's.

This data is from an auto grow almost two years ago. Note the comment on 6/8/22 — it wasn't until that date that I decided to get "lotsa light" on my plants. DeBacco mainly repackages research and I'd read or watched the research that he was speaking about but it wasn't until that date that I decided to "turn it up to 11".

The "Puck" is a Royal Blue puck from Rapid LED.






Perhaps, but it's not a function of the fact that the plant is an autoflower cannabis plant. It's a cannabis plant and, having spent a fair amount of time on a website dedicated to autoflowers, I can't say that they have any issues that are a function of being autoflowers. Cannabis will, generally speaking, do quite well when provided a sound grow environment.

Cannabis is a light whore thrives in high light, compared to other plants. The light saturation point for cannabis is 800-1000µmol, depending on strain and assuming that the other factors in your grow have been optimized. Cannabis is a C3 plant so it does not require darkness to carry out its "dark cycle" processing. This allows cannabis to be grown using a 24 hour photoperiod though most growers will use a light cycle ranging from 18/6 to 20/4.

If the environment is sound, 770µmol will get you a good harvest but, unlike nutrients where more is not better, crop yield and quality increase in an almost linear manner. I've done five auto flower grows and, by mid-veg, they were getting at least 850µmol with photoperiods ranging from 21/3 to 18/6.

nxsov180db said:

What’s that light schedule? 12/12, 18/6, 24/0? 770 you would want close to 12/12, it would be to much for a veg light cycle such as 18/6

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20/4

IndooorGardnerOhio said:

20/4

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I would think 14-16 hours would be the max on time per day with 770. 900 is about the max for 12/12 without co2 for example

nxsov180db said:

I would think 14-16 hours would be the max on time per day with 770. 900 is about the max for 12/12 without co2 for example

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It's a autoflower.. they typically run 20/4 or 24 hours with autos..

farmerfischer said:

It's a autoflower.. they typically run 20/4 or 24 hours with autos..

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Right, but the dli is too high so he needs to either reduce the light timing or intensity

Your environment / general plant health and other factors also play into what they can tolerate.
It’s recommended to judge the plants response to your light settings over “ specific charts “.
As they are only guides.

You can also balance appropriate settings between the dimmer control and distance to canopy.

Budzbuddha said:

Your environment / general plant health and other factors also play into what they can tolerate.
It’s recommended to judge the plants response to your light settings over “ specific charts “.
As they are only guides.

You can also balance appropriate settings between the dimmer control and distance to canopy.

View attachment 5356244

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Awesome, thank you! I did turn the light down so I am in the proper range for Veg now! So a 15 day old Auto would count as Veg Stage correct? Not sure what age they stop being considered a seedling?

IndooorGardnerOhio said:

Awesome, thank you! I did turn the light down so I am in the proper range for Veg now! So a 15 day old Auto would count as Veg Stage correct? Not sure what age they stop being considered a seedling?

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You are kind of needling the issue ( there is no straight answer ) - first see what your manufacturer of your light recommends ( height and power ).

Autoflower “ stages “ are kind of fluid ( as they don’t have a very long veg on average ) so trying to “ judge “ what stage it’s in is kind of moot. I usually throw about 30-50% of power setting at them , as they flourish i bump up ( but never go max ) reason being is it is unnecessary especially if you have a high powered led. I usually keep them at 800 ppf and thats it. It also saves wear and tear on led ( mid power diodes ) which ironically are even more efficient at mid power levels .

Thats why judging plants response - leaves that are lateral to light - no bleaching or light stress. It is too hard to say one person’s settings are gonna work for you. Then there is the VPD aspect if your grow too - humidity and temp. So many angles to this question.

Also “ praying “ leaves doesn’t necessarily mean its a good thing as it can be a response to too much light.

Budzbuddha said:

You are kind of needling the issue ( there is no straight answer ) - first see what your manufacturer of your light recommends ( height and power ).

Autoflower “ stages “ are kind of fluid ( as they don’t have a very long veg on average ) so trying to “ judge “ what stage it’s in is kind of moot. I usually throw about 30-50% of power setting at them , as they flourish i bump up ( but never go max ) reason being is it is unnecessary especially if you have a high powered led. I usually keep them at 800 ppf and thats it. It also saves wear and tear on led ( mid power diodes ) which ironically are even more efficient at mid power levels .

Thats why judging plants response - leaves that are lateral to light - no bleaching or light stress. It is too hard to say one person’s settings are gonna work for you. Then there is the VPD aspect if your grow too - humidity and temp. So many angles to this question.

Also “ praying “ leaves doesn’t necessarily mean its a good thing as it can be a response to too much light.

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Gotcha gotcha

Save me a smoke

Seeds don't do much for the first 3 weeks period. Me personally I don't turn down light intensity or adjust light height. What I do instead is place my unpotted seeds or clones on the ground increasing distance. From there they get up-potted bringing them closer, then training begins. I never adjust light intensity or height.

ProPheT 216 said:

Seeds don't do much for the first 3 weeks period. Me personally I don't turn down light intensity or adjust light height. What I do instead is place my unpotted seeds or clones on the ground increasing distance. From there they get up-potted bringing them closer, then training begins. I never adjust light intensity or height.

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you grow Autos or Photos or does this apply to both?

IndooorGardnerOhio said:

The following questions are for Auto Flowers.

Can too high of a PPFD, Such as 770 over a 14 day old plant Slow the growth?

Like it makes sense that too little light would slow growth, but can to much light also slow growth?

Click to expand...

Anything over 350 PAR and the edges of the leaves start to curl up on mine.

Good question. My mixed bag autos are kinda short at 4 weeks. Two of these are starting to flower. A little longer that the devils took. I'm expecting them to blow up in the next few weeks.

The devil Xxl I have kinda did the same thing. Stayed short, squat, and bushy till they started to flower n stretch.
This stage of growth is slow to me with the autos but once they take off they are pretty impressive plants.
I'm all over the place with the LEDs..lol. I'm just watching the plants n see how they respond. I don't have a good meter yet but then again I never had one before sooo..lol

greenmobster440 said:

Good question. My mixed bag autos are kinda short at 4 weeks. Two of these are starting to flower. A little longer that the devils took. I'm expecting them to blow up in the next few weeks.
View attachment 5356373
The devil Xxl I have kinda did the same thing. Stayed short, squat, and bushy till they started to flower n stretch.
This stage of growth is slow to me with the autos but once they take off they are pretty impressive plants.
I'm all over the place with the LEDs..lol. I'm just watching the plants n see how they respond. I don't have a good meter yet but then again I never had one before sooo..lol

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I use the Photone app on my phone. It may not be precise. But it gives me something to go by.

Blue_Focus said:

I use the Photone app on my phone. It may not be precise. But it gives me something to go by.

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I have that but am to tech stupid to calibrate..lol. I mean my mind just goes blank. Does that thing work proper right away or does it NEED calibration?

greenmobster440 said:

I have that but am to tech stupid to calibrate..lol. I mean my mind just goes blank. Does that thing work proper right away or does it NEED calibration?

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I use it as is.