Lighting Bigsm0 and the cob addiction

[verbalkent412]

Never EVER had plants this healthy. The true test for me is in flower when I can’t seem to come close. Just about every grow at flower has been a slow decline to yellow. I do have smaller strains going in here so the scrog isn’t filled like usual but I’m just as happy to see the plants get proper amount of space.

They are absolutely amazing! For reference the big space is 4x10 with 7 plants, 7 AutoCobs and the floor space they are taking up is 2.5x7.5 with 4 AutoCobs and not a yellow leave in sight. I love Greenleaf Nutrients!
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I think I’m going to give mega crop a go with my next grow when I pop my double grapes any advice on other nutes to use in conjunction?

 

[midIN]

I think I’m going to give mega crop a go with my next grow when I pop my double grapes any advice on other nutes to use in conjunction?

IMO first time using it and in soil I would run it only, I only say this from using it for couple months only and with their other nutes adds. I have both ways going and it alone is very impressive.

 

[BigSm0]

I think I’m going to give mega crop a go with my next grow when I pop my double grapes any advice on other nutes to use in conjunction?

I would stick with greenleaf only. Also should consider trying just the mega for your first go. I think I mentioned this in the past but we naturally tend to over do things. The guys at green leaf are a heck of a lot smarter than we are when it comes to nutrients and if they say it’s good on its own then I trust them.

Something else to think about. Price wise the additions are much more expensive than the mega alone. Anyone talking down their own profits must be serious.

 

[Heliman]

On DLI issues....

There is not a lot of info about DLI on the 'Net, but what I have read seems to suggest that at a certain DLI number (different for each plant species) photoinhibition will occur, which means the plant production processes will simply shut down ..there is not enough CO2 to support such intense light "production photosynthesis". This number for Weed would seem to be in the order of 35 DLl
when you consider that for a 18/6 model, the PPFD needed to get to 35 DLI would be 540 ....its a big amount of light !!!. Nevertheless this could be the optimum number for the plant's genetic potential ???

I believe that you can stoke the plant to higher DLI's but need CO2 injection to make it work.

At the more normal PPFD generated by Autocobs (around 240 PPFD, the 18/6 model generates a DLI of 16 or a 24/0 model generates 21. What I am thinking is that the plant will make it OK in any of the above scenarios, with yield maybe being a little better at higher DLI's ??? Of course, PPFD can be influenced by the distance light to plant, but at a certain point, burning occurs which sorta defeats the purpose here !!!

Again, all this is moot if the specrum and/or nute programme is screwed.....gotta love all those variables

 

[verbalkent412]

I would stick with greenleaf only. Also should consider trying just the mega for your first go. I think I mentioned this in the past but we naturally tend to over do things. The guys at green leaf are a heck of a lot smarter than we are when it comes to nutrients and if they say it’s good on its own then I trust them.

Something else to think about. Price wise the additions are much more expensive than the mega alone. Anyone talking down their own profits must be serious.

Lol I do have a tendency to over due things sometimes my first couple runs with autos I was burning the shit out of the from too much nutes but I’ve learned my lessononly thing that really sucks is I just bought a bunch of advanced nutrients so I’m going to use them up before I do a run with all mega (I planned on getting a small amount to begin with to use on 1 or 2 plants)

 

[Olde School Player]

raise your your lights up high! I an=m running only 2 autocobs in a 2'8" x2'8"x5' tent. I start them at 30" to get some stretch in veg and let them grow to the lightby end of flower they can be 12-14" from the light, depending on strain, some topping may be needed!

I start my AutoCOBs at about 40-42" or ≥1 meter above ground level, and let the plants grow from there. I hardy ever adjust much from that level throughout the grow. For example, an 18-inch plant (tallest mine ever get, or as tall I'd allow to it to get, with LST) would be about 24 inches from the lights usually with reflectors.

Still, like many, I try to do everything right, but my plants rarely ever stretch, never get tall at all. But I have 2 x Amare 150CR (Cree LEDs) in the same tent, so we can't conclude much from this about AutoCOB spectrum and stretch (vs. blaming the LEDs). I get high quality with average yield - a very good outcome in my view - now using AutoCOBs (supplemented with Amare 150CRs) and MegaCrop as my base nutes (at 1.5 g/L or 5.66 g/gallon, plus other complementary additives).

I don't want to trash BigSm0's thread here, but with apologies I'll quote long enough to redirect if you gents want to help me pursue this. I originally agreed with your suggestions of light height, but been there / done that. There's something else going on here.

Take a look at the Light Intensity thread in my sig. link below. I've grown fourteen rounds of autoflowers using HID and LED, and NONE of the LED grows have stretched, while ALL of the HID grows did. Some of the LED yields have been great, some have been shit. Some LED bud qualities have been great; a few have been shit (plants were SO dense as to have very poor color on the undersides and secondary buds). In short, inconsistent.
M​

y original theory when starting that thread was that light INTENSITY was affecting my stretch. So there's two ways to effect change to that, altering power or increasing distance as you suggested. I have two "system" style LED's that run 325Watts at wall; pretty powerful for a 5 sq. ft. tent. But they are enclosed system style lights so I couldn't readily lower power. So for my last grow I started light height (and stayed) at 39" - pegged at the top of the tent. The plant, as always, was pretty & healthy, but NO STRETCH. 3" tall and staying there. That's when I realized there must be something more than light intensity at play, So I changed my chase to spectrum. To confirm my suspicions I switched back to my trusty dusty old 250W HID, and the plant went to 16" in no time. Just what I'd always experienced under HID.
But what I'm looking to do is to recreate that result under LED. And if this makes any sense, I don't "understand" everything I "know" about growing. Lots of experience, great results, almost never screw up (knock on wood). But I'm not a lighting engineer, nor a botanist. So until I get past this stretch / no-stretch thing, I can't consistently count on the results I have come to expect from my autoflower grows.
I've convinced myself that COB's are in my future, and @BigSm0 has such a great rep on here that I already know I'll be purchasing a 4-pack from him. I just want to get closer to understanding the effect that light spectrum has on stretch before I pull out the old credit card once again. I know 2900 degrees kelvin generates consistent stretch with HID. But where should I be with LED? Nanometers to Kelvin conversion, any such thing? We'll see.

Stop by my thread and have a comment if you think of anything beyond light height!

 

[Olde School Player]

I think a big part of it is that autos are not the same as photos.... When I ran photos in the past it was “the more the merrier” with autos everything’s about light stress and lower wattages. As far as bud quality and density goes I’m running on average one cob per plant and the buds are insanely big, dense and resinous. Even with some heavy low stress training and scrogging I find the plants are plenty tall enough. If they start out shorter I usually decrease the hours of light down to 18 which helps. The full room picture was near the end of flower and I only had 11watts of light per square foot. Most people think it’s impossible but I don’t benefit by selling less lights lol.

As far as spectrum goes the 3500k cob is the best mix of veg and flower spectrums. The higher the number the more blue the light has, 4000k and 6500k which are more for veg. The lower the number the more red, 3000k which is more for flower. The middle is 3500k.

Thanks for the reply, @BigSm0 Totally concur, auto's are different from photoperiods. And I've chased all those theories. But unless a particular auto has a strong LowRyder influence in its lineage, there's no reason it should not exhibit some healthy stretch in its lifespan. My experience is that it's the 10 - 12" finished / final height where I get in trouble. If I can get a 16 - 20" plant and LST it down to 10 - 12" I am a happy camper. Bud quality and yields are awesome. But otherwise, either yield or bud quality suffers.
The light interval idea is one I had no considered, thanks for that. I'm so stuck on 20 / 4 that I needed a poke with a sharp stick to reconsider that!!! But I really feel your product has something else going on for it that other LED manufacturers do not. And since I'm not a lighting engineer, all I can speculate is that you have a better spectrum than most others. I'm still of the belief that light intensity has some effect on plant stretch, just not to the extent I originally thought. As soon as I get a bit closer to "understanding what I already don't know" I'll be in touch with an order. Thanks again.

Now that picture of your grow - that's a really good "you don't need 65w / sq. ft." sharp stick to poke me with. But my single plant grows typically fill a 4 to 5 sq. ft. area, so I think two COB's per tent would be more appropriate?

 

[pop22]

No stretch with LED??? that tent is 80" tall and the plant in the rear is bending against the roof

360 watts of QB 304 boards

 

[pop22]

And you right, going COB, etc, is what you want to get custom results by building the spread you want, spectrum, and dimming. Run them soft in veg crank them up in flower! Or not......... as our friend here shows us we have some rethinking to do on lighting. This may be where DLI comes in, give them the light they need not what we think they should get.

 

[BigSm0]

Thanks for the reply, @BigSm0 Totally concur, auto's are different from photoperiods. And I've chased all those theories. But unless a particular auto has a strong LowRyder influence in its lineage, there's no reason it should not exhibit some healthy stretch in its lifespan. My experience is that it's the 10 - 12" finished / final height where I get in trouble. If I can get a 16 - 20" plant and LST it down to 10 - 12" I am a happy camper. Bud quality and yields are awesome. But otherwise, either yield or bud quality suffers.
The light interval idea is one I had no considered, thanks for that. I'm so stuck on 20 / 4 that I needed a poke with a sharp stick to reconsider that!!! But I really feel your product has something else going on for it that other LED manufacturers do not. And since I'm not a lighting engineer, all I can speculate is that you have a better spectrum than most others. I'm still of the belief that light intensity has some effect on plant stretch, just not to the extent I originally thought. As soon as I get a bit closer to "understanding what I already don't know" I'll be in touch with an order. Thanks again.

Now that picture of your grow - that's a really good "you don't need 65w / sq. ft." sharp stick to poke me with. But my single plant grows typically fill a 4 to 5 sq. ft. area, so I think two COB's per tent would be more appropriate?

There are so many variables when it comes to growing. The best thing you can do is eliminate as many as possible. Genetics are number one, I have seen good results with good genetics and terrible lights, also seen poor results with good genetics, good lights and poorly applied nutrients. Even larger strains at times can have a shorter pheno. Good companies usually have a better success rate when it comes to individualizing them. I sent pop some seeds of the biggest autos I have ever grown, he ended up with super short plants that took 100 days to grow out. Mine would have been 8 feet tall if they weren’t in a scrog.

20/4 is a great schedule. I do recommend people give their plants a little rest which also helps them get a bit taller too. Spectrum also plays a big roll. I regularly grow with different spectrums, 3000,3500,4000 and 6500k. There is a noticeable difference between them as far as plant growth goes. As far as intensity you are absolutely correct. The more intense the lights are and the higher the ppfd the shorter the plants tend to be. If you wanted stretch stick a cfk in there and remove your real lights.

It’s been around a year since I discovered that the dli was really the main thing affecting my plants. Everyone else grew with higher wattages and did fine, I grew with the same lights but had burnt crisps. I was also on a photo prodominent forum too. It hit me one day when some photo grower was trash talking autos saying how they saved money by flowering with 12 hours on vs us up to 24 hours on. Then I did the math on how long I would veg for to get my auto sized plants as photos. Ext... in doing this it hit me that I was giving my plants twice the amount of light as they were. Photos 12 autos 24. It also struck me that most auto growers were using leds and I knew that these “300” watt leds were only around 25 par watts. Waaaay less than cobs or even hps. So most auto growers think they are giving more but are actually giving less. That’s why I think it hasn’t caught on. I can’t imagine someone going with 11 watts per square foot with a 300w eBay led. By face value that’s 27 sq feet lol. Now I’m here and my plants are better than ever. Less wattage, better spectrum, amazing growth and after recently adding up my lighting cost per month for an 8x20 filled with AutoCobs it’s crazy to consider a change.