First autos, when to increase par?

Ash4twenty

Well-Known Member
This is my first time growing autos , figured it’s time to stop listing to all the bad things people say about them . They look very healthy, but I’ve had my foot on the gas with them they seem to love it . Right now they are in early flower stretch is it time to turn up the light ? They look sad but it’s only case I just watered them about 40 mins ago .

Bruce banner auto by Herbie seeds
4x4
Light : Sf4000 at 55% I only have a lux reading of around 500 at canopy . Just raised vpd from 1.0 to 1.25
Should I turn it up ?




 
Cannabis loves light and research demonstrates that yield increases in an almost linear manner by about 5% for every additional 50µmols of light that hits the canopy. The light saturation point for cannabis is 800-1000mols in a non-CO2 enhanced environment. If you're at 750µmols, you could easily add >10% to yield (and quality) by turning up your light.

900µmols is ≈ 60k lux. That's a conversion factor of 0.015 which is good for a standard white light. Your light is a little blue heavy so 0.145 might be more appropriate. That conversion factor would put you at 62k.

My thinking, take it to 60k and see how they react. If they're are happy at 60k, go to 62. Lather, rinse, repeat.

Key point in giving your plants lots of food (light is food to a plant) is check for light avoidance behaviors - tacoing/canoeing or leaves rotating around the axis of the petiole. I've seen the latter happen once after I switched my light on to 100% power by mistake. A couple of the leaves had turned. I lowered the wattage and it took about 30 minutes for the leaves (two of them) to rotate back. I also "bent" the top part of a cola at about 1200µmols. It didn't bend back, though.

I document my light levels in my grow journals but I don't post updates that often since my grows have gotten pretty mundane.
 
Thanks ! What a detailed answer . Yea I pay attention to my girls all the time if I see the leaves turning from the light or what I call squatting where the plant is leaning away . I’m a photo person, so autos are new to me I read a lot about them being able to handle a lot more than photos. They have lots of co2 . Think I’m already at the red line with the light haha . I try going up by 5% at a time when I’m ready to turn it up . TLDR when my photos are at this stage I’m usually at 80% on my light . And these autos are showing me they don’t like it over 500 (60%). I’ll try 800 for a few hours then go back to 500 kind of ease them into it a little more . By your answer means I been shorting my self like 5-10% for no reason :(
 
See how they are slightly turned like it’s to much light . Looks like just that plant . Maybe I tuck that one in the corner

image.jpg


This is when I usually go to around 850
 
See how they are slightly turned like it’s to much light . Looks like just that plant . Maybe I tuck that one in the corner

image.jpg


This is when I usually go to around 850

Per the last photo, that's referred to a "praying" = plants that are getting a good amount of light. A better description is that the petiole is elevating the leaves toward the light and that's happening because the top side of the petiole is getting enough light to allow it to contract.

Photo avoidance would be when the leaves rotate around the axis of the petiole. Think of how we would tilt Venetian blinds to block the sun - leaves reorient that way to reduce the surface area exposed to the sun.

Those gals are doing well in terms of light but their color is dark green which raises a question about nitrogen levels.

In terms of lighting the plants - they're not topped so you're going to have a lot of apical stems sticking up and that makes it hard to get a uniform light cast. Are they supple enough that you can do some LST? If not, you'll be doing some super cropping.

Nice looking plants, no question. I do think that they could have used more light earlier in life. My comment based on the fact that your light is heavy blue so you should have compact, bushy plants but the internodal space is pretty big. That leads me to think that they could have used more photons as kids but they're healthy plants so they should respond really well to lotsa light.
 
Yea very green ( think the camera filter adds some )first time growing this strain and the description said they were very hungry plants , but they seem to be just average . I did skip their feeding this week and just gave them ph water . In a few more days I’m sure they will I’ll be fine I have a journal on them we will see. Just since the first message they seem to be loving the light .
 
Thanks ! What a detailed answer .
Heh, you're very welcome. I get a lot of different responses - yours is quite appreciated.

Yea I pay attention to my girls all the time if I see the leaves turning from the light or what I call squatting where the plant is leaning away .
Good to hear. I've only seen a couple of instances where plants were truly suffering from too much light. It's not easy to do that with an LED. Seeing that you're attentive, you should be able to push them pretty hard if you want.

BTW, "push them hard" is a term used by Dr. Bruce Bugbee and he refers to that when plants get > 45mols.

I'm a Bugbee acolyte but I've relied research from multiple sources not just Bugbee. His YouTube videos are time well spent.

Oh, one of the photos shows the sensor from an AC Infinity device. What equipment is that?

I’m a photo person, so autos are new to me I read a lot about them being able to handle a lot more than photos.
Too funny - I've done five auto grows and am in week 4 of flower in my first photo grow.

Interesting about autos handling more light than photos. They're both cannabis. A terminology issue - PPFD vs DLI. PPFD = how heavy is it raining vs DLI = how much rain have we gotten in the past 24 hours.

Cannabis maxes out at ≈1k µmols, so sayeth the pointy headed people. I've run my autos in the mid-900's for 18-20 hours which means they end up with a DLI ("daily light integral") in the 70's. Cannabis is a C3 plant so it can grow in 24 hours of light. Plants have a "dark cycle" but it has nothing to do with illumination - it's a description of processes that don't involve photosynthesis so "sleeping" is an absolute misnomer.

Photoperiod cannabis will continue to veg as long as you don't reduce the hours of light to 12/12. Once you flip it, though, you can still hit it with the same intensity of light (sativa, indica, or ruderalis) but, since a photoperiod is only illuminated for 12 hours a day I flower, the DLI is reduce. Below is the chart for my current grow:

1680829423275.png



They have lots of co2 . Think I’m already at the red line with the light haha . I try going up by 5% at a time when I’m ready to turn it up . TLDR when my photos are at this stage I’m usually at 80% on my light . And these autos are showing me they don’t like it over 500 (60%). I’ll try 800 for a few hours then go back to 500 kind of ease them into it a little more . By your answer means I been shorting my self like 5-10% for no reason :(
Per my previous response, your plants look happy. One of my postings when my plants looked like that was "If they were any happier, they'd have to get a room."

I did read one grow journal where the grower could not get > 500 µmols which is a sign of a serious problem. It took a while to troubleshoot the grow but it turned out that he had allowed the bottom few inches of soil to dry out so the roots in that part of the pot were in bad shape. Once he got that squared away, he was able to increase light levels.

Your gals are looking good. Feed 'em well and you'll get a lot of weed.
 
Yea very green ( think the camera filter adds some )first time growing this strain and the description said they were very hungry plants , but they seem to be just average . I did skip their feeding this week and just gave them ph water . In a few more days I’m sure they will I’ll be fine I have a journal on them we will see.
You're on it. Great.
I'll check out your journal.

Just since the first message they seem to be loving the light .
Glad to hear that!
 
A wise man once told me that from the time they are seedlings, with each new leaf they can handle a little more light. Following that advice I start off low at around 7k LUX and steadily increase a bit each week, to a max of about 45k LUX in late Veg. In Bloom, I blast them with everything I've got, with up around 80k LUX
80k lux is CO2-enhanced level lighting. Any sign of bleaching of the flowers?

Some spots on my current grow have been in the mid-1100's. They showed no sign of light avoidance but I moved them around a bit to reduce PPFD, just because… :)

I should revisit that, I s'pose.
 
Heh, you're very welcome. I get a lot of different responses - yours is quite appreciated.


Good to hear. I've only seen a couple of instances where plants were truly suffering from too much light. It's not easy to do that with an LED. Seeing that you're attentive, you should be able to push them pretty hard if you want.

BTW, "push them hard" is a term used by Dr. Bruce Bugbee and he refers to that when plants get > 45mols.

I'm a Bugbee acolyte but I've relied research from multiple sources not just Bugbee. His YouTube videos are time well spent.

Oh, one of the photos shows the sensor from an AC Infinity device. What equipment is that?


Too funny - I've done five auto grows and am in week 4 of flower in my first photo grow.

Interesting about autos handling more light than photos. They're both cannabis. A terminology issue - PPFD vs DLI. PPFD = how heavy is it raining vs DLI = how much rain have we gotten in the past 24 hours.

Cannabis maxes out at ≈1k µmols, so sayeth the pointy headed people. I've run my autos in the mid-900's for 18-20 hours which means they end up with a DLI ("daily light integral") in the 70's. Cannabis is a C3 plant so it can grow in 24 hours of light. Plants have a "dark cycle" but it has nothing to do with illumination - it's a description of processes that don't involve photosynthesis so "sleeping" is an absolute misnomer.

Photoperiod cannabis will continue to veg as long as you don't reduce the hours of light to 12/12. Once you flip it, though, you can still hit it with the same intensity of light (sativa, indica, or ruderalis) but, since a photoperiod is only illuminated for 12 hours a day I flower, the DLI is reduce. Below is the chart for my current grow:

1680829423275.png




Per my previous response, your plants look happy. One of my postings when my plants looked like that was "If they were any happier, they'd have to get a room."

I did read one grow journal where the grower could not get > 500 µmols which is a sign of a serious problem. It took a while to troubleshoot the grow but it turned out that he had allowed the bottom few inches of soil to dry out so the roots in that part of the pot were in bad shape. Once he got that squared away, he was able to increase light levels.

Your gals are looking good. Feed 'em well and you'll get a lot of weed.
Wow that’s a lot to take in but I got it , I have the cloud line pro 6 with the 6” oscillate fans. I’m sold on ac other than the light , And tent . This man I watch was saying that they released certain hormones during night to increase thc levels? Or possible bud growth . Photos are so nice and forgiving . I could lst train them but I really was running this as an experiment how they grow . They are all the same hight other than that 1 . I’ll top her if needed in the next day or two . Oh I turned the light up a little more as well haha
 
A wise man once told me that from the time they are seedlings, with each new leaf they can handle a little more light. Following that advice I start off low at around 7k LUX and steadily increase a bit each week, to a max of about 45k LUX in late Veg. In Bloom, I blast them with everything I've got, with up around 80k LUX
I always want to just blast them in flower. really give them the beans lol
 
80k lux is CO2-enhanced level lighting. Any sign of bleaching of the flowers?

Some spots on my current grow have been in the mid-1100's. They showed no sign of light avoidance but I moved them around a bit to reduce PPFD, just because… :)

I should revisit that, I s'pose.
Once in a while I get a little bleaching and/or burning if they get up too close to the light. I am getting better about that though, and at about a foot away they are getting 65-75k depending on where they are at, and they seem to be happiest right in there. Haven't played with co2 for years and rely instead on excellent air movement.
 
@Ash4twenty "This is my first time growing autos , figured it’s time to stop listing to all the bad things people say about them ."

That's a wise choice in my opinion. I have grown about 50:50 photos and autos and I love them both. I don't agree with most of the hate autos get. The only thing that is a pain is that if you buy an auto because you love the photo version of a strain, you don't always quite get what you are after. If you just grow an auto strain that sounds good, there's lots that easier about autos as well as harder in my opinion.

You've already got great advice on the light levels so all there is to say is best of luck with the grow :)
 
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