OneHitDone
Well-Known Member
If everyone wants to grow exactly the same variety for a completely lighting/grow method only comparison - these are what I am using:
http://www.johnnyseeds.com/p-9700-rex.aspx
All COB Users - Lettuce Grow Challenge!!
- Thread starter OneHitDone
- Start date
http://www.johnnyseeds.com/p-9700-rex.aspx
ilam
Member
*I think 3500k Leds are too red dominant for lettuce production.
[Leaf Shape, Growth, and Antioxidant Phenolic Compounds of Two Lettuce Cultivars Grown under Various Combinations of Blue and Red Light-emitting Diodes]
http://hortsci.ashspublications.org/content/48/8/988.full.pdf
Also remember that some lettuce is more HIGH PPFD friendly than others, for example buttercrunch is known to be sun-hardy.
[Leaf Shape, Growth, and Antioxidant Phenolic Compounds of Two Lettuce Cultivars Grown under Various Combinations of Blue and Red Light-emitting Diodes]
http://hortsci.ashspublications.org/content/48/8/988.full.pdf
So i'm thinking of maybe something along the lines of CITI 1212 @ 4k 80 CRI
Also remember that some lettuce is more HIGH PPFD friendly than others, for example buttercrunch is known to be sun-hardy.
OLD MOTHER SATIVA
Well-Known Member
if i was going for just making green leaves i think i would go higher than 3500 k..that said we are doing pretty good with the greens with the 3500k led tubes
OneHitDone
Well-Known Member
Here's a couple of the same variety growing under my "Sauce" Spectrum.
Interesting the leaf shaping difference vs a straight K temp cob.
Will be interesting to see how these look at maturity
Interesting the leaf shaping difference vs a straight K temp cob.
Will be interesting to see how these look at maturity
I just wanted to thank you all and encourage you to keep up the good work. I joined the forum just for this thread.
I am about to start a new lettuce garden under Citizen CLU048-1212s @ 4000k but I don't know if my results will be very useful since I am only using the LEDs to supplement sunlight through a south facing window and to control the lighting period. I can compare it with some lettuce grown in the same sunlight, but supplemented by 6500k Vitalume T5s. Unfortunately, the T5s are on my vertical ebb and flow herb garden and the COBs will be a purely lettuce DWC. Way too many variables to compare but I will post pictures in the coming weeks just because I love this thread. The DWC will be running this Sunday and I have some seedlings that were planted on 10/26 as test dummies that will go in then. The last parts for my light should be in by the end of next week. I like to harvest on Sundays so this Sunday (11/6) I will start two Rouge de Hiver and two Grand Rapids. They will spend 2 weeks in the basement including germination in darkness and early growth under a CFL. Then I will put two in the DWC and two in the ebb and flow. Every Sunday I will plant again so that I will eventually fill in the garden with five pairs of lettuce with one week between each pair. At the 5th week (+2 weeks in the basement) I will harvest. I will only grow one pair in the ebb and flow because that's where I grow my herbs.
The advice I was given was that the 4000k COBs are "fine", keep them at 20000 lux on an 18/6 schedule. In my case that will include sunlight, so it probably makes this useless for the purposes of this thread, but I want to be a part of it.
My goal isn't so much science as it is 2 heads of lettuce per week for my family.
I am about to start a new lettuce garden under Citizen CLU048-1212s @ 4000k but I don't know if my results will be very useful since I am only using the LEDs to supplement sunlight through a south facing window and to control the lighting period. I can compare it with some lettuce grown in the same sunlight, but supplemented by 6500k Vitalume T5s. Unfortunately, the T5s are on my vertical ebb and flow herb garden and the COBs will be a purely lettuce DWC. Way too many variables to compare but I will post pictures in the coming weeks just because I love this thread. The DWC will be running this Sunday and I have some seedlings that were planted on 10/26 as test dummies that will go in then. The last parts for my light should be in by the end of next week. I like to harvest on Sundays so this Sunday (11/6) I will start two Rouge de Hiver and two Grand Rapids. They will spend 2 weeks in the basement including germination in darkness and early growth under a CFL. Then I will put two in the DWC and two in the ebb and flow. Every Sunday I will plant again so that I will eventually fill in the garden with five pairs of lettuce with one week between each pair. At the 5th week (+2 weeks in the basement) I will harvest. I will only grow one pair in the ebb and flow because that's where I grow my herbs.
The advice I was given was that the 4000k COBs are "fine", keep them at 20000 lux on an 18/6 schedule. In my case that will include sunlight, so it probably makes this useless for the purposes of this thread, but I want to be a part of it.
My goal isn't so much science as it is 2 heads of lettuce per week for my family.
OneHitDone
Well-Known Member
Lettuce should rock n roll in aero
OneHitDone
Well-Known Member
Here's a Friday night "Secret Sauce" lettuce update
I will copy @Evil-Mobo with Friday updates on these
I will copy @Evil-Mobo with Friday updates on these
So is the "secret sauce" filling in the green gap? What's the panel again?
OneHitDone
Well-Known Member
Eliminating the big dip around 500nm in most white led's + a few diodes over to the blue/violet end.
Cheap China UFO and direct from china 3W led light beads
Nice. Didn't you hear the greens are useless?
But now you know you'll have to add each of those in one at a time, right?
OneHitDone
Well-Known Member
I will get a good enough idea what the spectrum will do between real world test and the spectrum calculator I used to come up with the recipe.Nice. Didn't you hear the greens are useless?
But now you know you'll have to add each of those in one at a time, right?
But you are right, it would take adding specific nm diodes one at a time and testing under lab like conditions to make any real scientific conclusions.
That is what is truly lacking in the led industry. All these "companies" just make speculations but don't have real documented science behind their products.
Sure Johnny grew some weed that looked ok in photo's with x cob. But what was the quality really like and what if there is a better spectrum to be had with a truly Horticultural targeted spectrum
These videos are interesting. They are about the effects of far red on lettuce and flowering plants.
Edit: Seems like maybe the red to blue ratio should be equal or favor red and a supplemental far red added. It's probably not this simple but if a 100W 3500k white LED had about an even amount of its red and blue peaks you could supplement with up to a 50w far red LED. Seems maybe a deep blue could maybe be used just a few days before harvest for coloring.
Edit: Seems like maybe the red to blue ratio should be equal or favor red and a supplemental far red added. It's probably not this simple but if a 100W 3500k white LED had about an even amount of its red and blue peaks you could supplement with up to a 50w far red LED. Seems maybe a deep blue could maybe be used just a few days before harvest for coloring.
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I am thinking of adding a 100W full spectrum chinese led (http://www.ebay.com/itm/High-Power-100W-380nm-840nm-Full-Spectrum-LED-Chip-SMD-Grow-Light-Bead-Lamp-COB-/172345063028?hash=item282090f674:g:EEoAAOSwGtRXw5yw) to my 2 x Citizen CLU048-12-12 @4000k. That would add a better far red ratio and add a touch of UV and IR. 
Green=4000k Blue=Full Spectrum
Green=4000k Blue=Full Spectrum
OneHitDone
Well-Known Member
Without a spectroradiometer how can we know what the effective at the canopy spectrum will really be like when combining different nm led's?
I used an online calculator for my "Sauce" but I doubt my cheap china led light beads very accurately match what I was after.
Not much scientific value to what I am doing, but expanding the spectrum of the white COBs seems like where this is going to me. This would basically end up being 1W "full spectrum" to 2W 4000k.
OneHitDone
Well-Known Member
"The Sauce" Lettuce coming along
Growth seems a slow compared to what I am used to. Possibly cool temps and lack of IR? Definitely not adding a heater to increase transpiration lol
Growth seems a slow compared to what I am used to. Possibly cool temps and lack of IR? Definitely not adding a heater to increase transpiration lol
May be slow growth, but looks like some text book lettuce to me. The advice I got seems pretty confident that the problems people are having is just due to too much light. This person is saying you have to get your daily light integral down around 17 which is a little more than half what is suggested for cannabis and should work out to around 20000 lux @ 18 hours per day. I am going to go ahead and add in the full spectrum cob because I don't think it will hurt, but I was also told that optimal far red is going to vary for each type of lettuce.