The Ideal spectrum.
- Thread starter Rahz
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ChiefRunningPhist
Well-Known Member
I've heard people suggest raising room temp when using LED, due to the lack of IR in LED. To me, this seems like a delinquency of the light, rather than a grow environment issue. This is how I'm looking at VPD. I agree that ambient temp and RH are important, but am trying to determine the WVs responsible that seem to offset less than perfect growing conditions in nature (un-ideal RH in nature, and un-ideal temp in nature). Are there WVs or WV ratios that help the plant control its transpiration (imo, what the VPD hypothesis boils down too)? It seems HPS and CMH growers are posting less about VPD issues, but I'm not sure why. Trying to tease out if it's coicendental(?) or if online forums have an innate selection bias toward LED and tech types, ect(?). I personally didn't have these issues when I grew with HPS.
If low RH or poor VPD causes greater transpiration rates, shouldn't they offset? Shouldn't they correct themselves? The lower the RH the greater the transpiration, which leads to RH increase which leads to less transpiration ect...
I'd like to use a light that doesn't require a space heater to raise ambient or a humidifier to offset a "VPD sensitivity" (if this is actually the case). I think LED is great, but think it could be even better. I think a widening of the typical SPD used now is right around the corner if not being done currently, and individual WV range scheduling will be close behind (mimicking cloud cover, sun position, intensity, ect by programmed SPD manipulation/tuning and brightness mgmt).
LED deficiency could be nutrient too. I'm not sure yet, but I think regardless, that LED lights will evolve. I'm fairly confident that WV can be used to signal the plant to do what we want, maybe its just naivete though as I'm not really versed and more or less a gut feeling based on what I've read.
If low RH or poor VPD causes greater transpiration rates, shouldn't they offset? Shouldn't they correct themselves? The lower the RH the greater the transpiration, which leads to RH increase which leads to less transpiration ect...
I'd like to use a light that doesn't require a space heater to raise ambient or a humidifier to offset a "VPD sensitivity" (if this is actually the case). I think LED is great, but think it could be even better. I think a widening of the typical SPD used now is right around the corner if not being done currently, and individual WV range scheduling will be close behind (mimicking cloud cover, sun position, intensity, ect by programmed SPD manipulation/tuning and brightness mgmt).
LED deficiency could be nutrient too. I'm not sure yet, but I think regardless, that LED lights will evolve. I'm fairly confident that WV can be used to signal the plant to do what we want, maybe its just naivete though as I'm not really versed and more or less a gut feeling based on what I've read.
coreywebster
Well-Known Member
Yeah I had this convo with Jessilikestogrow and he was of the opinion that upping the co2 would help.
Yet to test that out though.
I feel with some lighting sources the relationship between leaf temp and intensity or closeness is linear where with white LEDs its not, so the big increase in intensity doesn't result in the needed increase in leaf temp to aid transpiration and nutrient uptake.
Edit that was in reply to an earlier comment. In case it wasn't clear.
Yet to test that out though.
I feel with some lighting sources the relationship between leaf temp and intensity or closeness is linear where with white LEDs its not, so the big increase in intensity doesn't result in the needed increase in leaf temp to aid transpiration and nutrient uptake.
Edit that was in reply to an earlier comment. In case it wasn't clear.
captainmorgan
Well-Known Member
Or possibly with the spectrum out of balance it throws some plant processes out balance and when it reaches a certain level it has a domino effect.
nachooo
Well-Known Member
Yes... I think the same..I like leds a lot....but.... for me to use them and obtain benefits....I have to control VPD perfectly...and other things...Wish to have less complex lights to work with..althought I have learn a lot thanks to leds... HPS was easy..but their heat and efficiency are a not go for me. Certainly we are lacking something...regarding wavelenghts at least in veg mode ...Also with leds ours Red/far red ratios are not natural at all..... Far red has action in stomata too... I have read some papers on it... We are pushing a lot towards reds and deep reds... maybe creating some sort of imbalance..
captainmorgan
Well-Known Member
I think the balance theory makes some sense when you look at what the plant looks like when grown under different light sources. It's been mentioned before by others and I've seen it first hand. I've given cuts to friends that grew with HPS and CMH and my plant actually looked like a different strain grown under LED.
nachooo
Well-Known Member
Same has happened to me..also different terpene profile with same clones
captainmorgan
Well-Known Member
With GG#4 the appearance difference can be quite drastic grown under LED. I will say that with outdoor and HPS the appearance is much closer to the same. It even affects the look of the structure.
ChiefRunningPhist
Well-Known Member
Haha nice tell him I said hi, I've heard this as well. Definitely sounds plausible to me. The more I look at the solar SPD the more I toy around with going up to 10%-15% of my total light as FR. I've been looking at all these research papers, but it just kinda hit me (again), there really is no better grow light than the sun. You can make a light with all sorts of peak absorption target ranges ect, but at the end of the day I'd still pick the sun. Science changes with time (ex. dont eat egg yolks, ok eat egg yolks), and I'm wondering if enough time passed (to allow for the discovery), if we find that the best SPD is really very similar to the solar spectrum.
nachooo
Well-Known Member
According with the graphs you posted...
LM301H_CRI80_3500K red 14 far red 2.... a 7 ratio!!! with reds added (lot of new boards) it will be much more...
Solar emission red 13& far red 13% ...almost 1/1 ratio..a little more on the red side...
What ratio are you using in veg?
jarvild
Well-Known Member
At least you guys are figuring it out !
I really don't pay attention to VPD as long as my rh is between 50-65%. I also don't worry about temps as long as as it's between 72-82 degrees F.
Plant's grown out side have can have a wide range of conditions they will go through during their life cycle.
DLI, your starting to get here. Simple fact is that hitting a plant with 600 ppf for 18 hours a day will give you a DLI of around 38, twice as much as you need for a young vegging plant from my general gardening experience. Hell, leafy green veggies do just fine with DLI's in the upper teens to low 20's of DLI.
Here's an example of just an experiment with regards to all white spectrum and white base with enhanced UV, blue, photo reds, far reds and IR.
Plants on the right had an extra week of veg and are 3 weeks behind on flower.
I am here to help you guys figure it out, so any questions let me know.
I really don't pay attention to VPD as long as my rh is between 50-65%. I also don't worry about temps as long as as it's between 72-82 degrees F.
Plant's grown out side have can have a wide range of conditions they will go through during their life cycle.
DLI, your starting to get here. Simple fact is that hitting a plant with 600 ppf for 18 hours a day will give you a DLI of around 38, twice as much as you need for a young vegging plant from my general gardening experience. Hell, leafy green veggies do just fine with DLI's in the upper teens to low 20's of DLI.
Here's an example of just an experiment with regards to all white spectrum and white base with enhanced UV, blue, photo reds, far reds and IR.
Plants on the right had an extra week of veg and are 3 weeks behind on flower.
I am here to help you guys figure it out, so any questions let me know.
nachooo
Well-Known Member
Nice test. Nice plants
Can you tell us which wavelenghts in infrared and uva and their % ...and far red ratio?
Thanks
mustbetribbin
Well-Known Member
I find it funny that we need heat and IR to balance out many a LED grow, but yet nobody dares mention the old lost and forgotten technology found in Incandescent, if heat and IR is what needs to be supplemented to an LED setup then why not just add an efficient heater that also emits light in order to produce the heat it makes? The spectrum that incandescent makes is actually ideal for flower and late flower anyhow, so the need to supplement it's use would not be necessary throughout the full grow period, just during flower or late flower mostly, this is when plants need the full spectrum the most in order to pass life onwards to the next generation onwards, naturally.
Who's up for a old tech meets new tech grow, I know I am.... all the resources are already available, don't need to wait on some mass produced corporation to provide you with newest tech for 10x the cost just to match the ideal spectrum that we are after, I think incandescent and halogen both deserve a glance over at least as far as supplemental lighting goes, they aren't as wasteful as people think if you add the necessity into the equation that heat/IR is necessary to promote optimal growth under LED.
Also while we are on the subject of IR let me also include that UV is a great necessity for triggering increased cannabinoid production within Cannabis, and increased terpene production overall, one thing that we must not assume is absolutely perfected just yet is these supposed UV emitting LEDs, just in the same way the advertised Full-Spectrum bulbs and lights advertise that they emit the full Sun like spectrum, we all know under spectral testing these lights fall short of their advertising, and that Full Spectrum is not approachable with any single source of light technology, therefore UV light that is emitted from these LEDs will also not be exactly as found in normal sunlight and that the full spectrum of UV cannot be emitted from one single source, which brings me to my point in that fluorescent technology should not be overlooked when attempting to match the authenticated full spectrum UV light that the Sun releases. I'll admit flouros do have a risk factor of they burst, but if you're willing to accept the risk then they actually do grow some decent plants on their own, with other light tech added they do hold their own as a functioning unit in the spectral light range and UV they emit.
I'm all for LED technology, however I'm not willing to wait for them to finally design something that is genuinely an ideal full spectrum light with all the bells and whistles, and then charge me X amount of money, when I could have produced the same results with just a little ingenuity and know how.
That's what I'm currently growing under, seeing good results so far, now that summer is almost over I'll be able to take more advantage of the incandescent I mentioned above, nice summer like heat/IR/UV for mid winter growing.
Who's up for a old tech meets new tech grow, I know I am.... all the resources are already available, don't need to wait on some mass produced corporation to provide you with newest tech for 10x the cost just to match the ideal spectrum that we are after, I think incandescent and halogen both deserve a glance over at least as far as supplemental lighting goes, they aren't as wasteful as people think if you add the necessity into the equation that heat/IR is necessary to promote optimal growth under LED.
Also while we are on the subject of IR let me also include that UV is a great necessity for triggering increased cannabinoid production within Cannabis, and increased terpene production overall, one thing that we must not assume is absolutely perfected just yet is these supposed UV emitting LEDs, just in the same way the advertised Full-Spectrum bulbs and lights advertise that they emit the full Sun like spectrum, we all know under spectral testing these lights fall short of their advertising, and that Full Spectrum is not approachable with any single source of light technology, therefore UV light that is emitted from these LEDs will also not be exactly as found in normal sunlight and that the full spectrum of UV cannot be emitted from one single source, which brings me to my point in that fluorescent technology should not be overlooked when attempting to match the authenticated full spectrum UV light that the Sun releases. I'll admit flouros do have a risk factor of they burst, but if you're willing to accept the risk then they actually do grow some decent plants on their own, with other light tech added they do hold their own as a functioning unit in the spectral light range and UV they emit.
I'm all for LED technology, however I'm not willing to wait for them to finally design something that is genuinely an ideal full spectrum light with all the bells and whistles, and then charge me X amount of money, when I could have produced the same results with just a little ingenuity and know how.
That's what I'm currently growing under, seeing good results so far, now that summer is almost over I'll be able to take more advantage of the incandescent I mentioned above, nice summer like heat/IR/UV for mid winter growing.
ChiefRunningPhist
Well-Known Member
I use 6500k E27 mixed in with 3500k QB304+'s (48 660nm reds on each 304). Then I switch the E27 6500k for E27 3000k in bloom but keep the 3500k QBs. I don't have a spectrometer and haven't tried to calculate %s on my current setup as it'll be the old one as soon as the new one gets finished. I'd say less than 5% total FR.
@mustbetribbin others have also recommended the incandescent. You might be on to something. You're right about not being able to achieve all UV WV with LED, that is one drawback. I'm trying to have a single fixture capable of replicating the solar spectrum, but also not tying to blend the tech types, though you may have the right idea. Disregarding operating costs, at the end of the day, how you create your spectrum really means very little. Teknik suggested incandescent to me awhile back too, you guys could be on to something.
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jarvild
Well-Known Member
As far as a percentage I've never figured that out since using a white base as I'd have to figure what overlapping spectrum from the white LED's. I can tell you the ratio on the supplements diodes for the 70 watts of power they provide as they are simple single star LED from Rapid LED.
There's 6 bars with 6 diodes on each bar for a total of 36 diodes for the supplements fixture, I'll have to go back to my notes for the exact numbers as the fixtures are 2 years old now but the reds are like 18 photo reds (660nm) to 7 far reds (720-740 nm) to 5 IR (840-870nm) diodes.
ChiefRunningPhist
Well-Known Member
jarvild
Well-Known Member
If your talking Low Stress Training , then none. All plants I test are au-nuatural, meaning I don't fuck with the plants in anyway, just let them do their thing.
IR is 840--870 NM.
The supplements side is 9 3000k white base LMC561c strips with the strips tuned down to pull a total 270 watts from the wall with the supplements.
The all whites are a mix of 3500 an 4000k strips pulling 268 watts from the wall.
Trying to run the plants on full power on the supplement side is just too much light for them in that 3x4' area.
Full power on the supplement side ( 340 watts from the wall).
ChiefRunningPhist
Well-Known Member
Haha nice, and I was meaning leaf surface temp. Curious how much the FR and IR contributed to a higher plant temp.
mustbetribbin
Well-Known Member
Haha, thanks for the reply @ChiefRunningPhist, yeah I threw a bit of a joke in there as far as incandescent being mentioned on the forum, it really isn't brought up too often though, so I just wanted to put that out there to see what others think about the old tech/new tech idea lol and I'm sure others have reached this same conclusion that I have way before I ever did lol.
But hey in regards to operational costs, what about the idea of the LEDs being ran full time, while the incandescent could be ran on say a 6hr-8hr timer stimulating afternoon Sun, while also not consuming quite as much energy? Most plant lights we use for growing over saturate the plants with a specific type of spectrum anyhow, much of this spectrum is not necessary for the full duration of the day, the plants need the light to complete cycles each day, once that saturation point for that day is reached and the plant completes a given amount of cycles that were necessary for growth that given day, then that spectrum will not be as necessary until the following day when another set of cycles are set to take place, basically all I'm saying is maybe our spectrum of lights doesn't have to be used full time for the plants to respond to the added spectral/IR/UV benefits that each light source emits. Plants can only utilize a given amount of photons each day for the preceding set amount of cycles that will be allowed to for-go for the duration of that given day.
Sometimes plants must undergo being given only a few hours of direct sunlight in the wild, and many plants are still able to survive this way and pass on new seeds still and continue their species just the same, isn't this a hint to us that maybe our lighting setups don't need to be ran full time throughout the day, isn't this a hint that there may be room for hidden extra efficiency instinctually hidden within the survival mechanism that all plants contain built into their DNA?
Large plants can be grown under semi-intermittent light as long as the intensity and set number of utilisable hours of light/intensity running per day is reached.
Does anyone here agree with this above statement? I'm just trying to collect ideas from others, nothing I say is by any means presented as set in stone in this regard. Thanks guy's.
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jarvild
Well-Known Member
The only time I worry about PPF is for DLI total. I also sort of have a problem with the term PPFD as with PPF the area is already stated with the density of photon distribution in a m/sq per second so it's just redundancy.