Ca++
Well-known member
385nm is particularly good at attracting bugs, to feed them
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LED and BUD QUALITY
- Thread starter Tropical Sun
- Start date
great! then I spend less on feeding the lizard
Rocket Soul
Well-known member
Do you have any more scope pics of hps vrs led?
I'm not sure I follow you. My plants aren't any of those things. This was two days ago, not a selective photo. Some real old-school genetics in there, including an Atomical Haze germinated from almost 20-year-old seeds, and an old Aussie super skunk variety germinated from 15-year-old seeds.
This is the LED I use. No lack of red or blue/violet/UVA to activate carotenoids.
Not true. There are some LED lights out there that are "true" full spectrum.
If you define "full spectrum" as 400-700nm and beyond then you are partially correct that most LED grow lights don't include the violet end of the spectrum.
How does IR help the plant when ambient (and leaf) temperatures are already optimal? Many of us grow indoors where we control the temperature. LEDs do produce heat – about 40% of a fixture's total output is IR, and that is for the most efficient LED fixtures. Budget models can produce 50% or more. This includes the driver and wiring thermal losses.
The advantages of LEDs are multi-fold.
Efficiency
Spectral control
Longevity
More head room
Less waste
Every nation in the world is swapping out HPS street lamps for LED. Why? Cheaper. No bulb changes and much lower running costs. LED is getting better every day while single-end HPS technology has been pretty much the same for 60+ years.
One point missing from these arguments is that nutrient formulas have been developed under HIDs and haven't really changed much to suit lower transpiration LEDs. Cannabis has also been selectively bred indoors under HPS for 40+ years, so phenotypes that perform better under HPS have been propagated on a larger scale.
Rocket Soul
Well-known member
We usually tend to agree on most but im leaning towards the IR bandwagon, or at least in testing it a bit if i can find the amps. I wanna see it for myself.
Have a look see a few pages back to Grey faders grow results. If you remove the whole argument about how he got his light (led light bulbs + incandescent) and just check results based on 1200ppfd + some incandescent (right in 680 and above all thru the infrared) : thats nice looking results which i dont mind testing myself. The thing is actually seeing and quantifying the benefits of having a little of "HPS on tap" next to your leds. May also be a local climate thing; we get so cold winter that we really need the heat and AC heating, while fairly efficient compared to a radiator, have a tendency to dry the air too much. While gas burning also mess with environment; it comes with humidity and co2 which can sometimes be too high or just not controllable enough.
This is why im thinking some low watt halogen spots might be a nice experiment. Ill see if i can get this setup this run along with the new strips but maybe on another section.
As for HPS; if youre growing in an open space the game is a little different with maintaining good led climate; id rather drop a couple of bulbs in than putting in a 2000w radiator. HPS can be thought of as a radiator that also gives light.
how true..... there was a very special lady in them old jock seeds...
CMH + 2800K CRI95 LED
dogzter
Drapetomaniac
You should drop in the ol farts thread prawn a lot of the old PG crew are in there.
arb says hello.
mm4n
Well-known member
Yes, but the lens quality is too low to draw any conclusions.
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My current setup is a kind of HPS-vs-LED test: at the moment, under HPS the leaf growth is visibly higher than under LEDs, BUT if you look closely, the density of bloom spots under LEDs is almost twice than under HPS.
Attachments
Janborrego
Well-known member
greyfader
Well-known member
so, by dropping the 5000k altogether by switching them all out for 2700k, which has the lowest blue portion i could find, and then adding the incandescent, which has a greater portion of red in the par range than the sun, i radically shifted the blue/red ratio.
by using multiple low-wattage (6x25watt) incandescents, i was able to keep them on the same plane and proximity as the LEDs so their IR output also was certainly felt by the plants.
there is a difference between heat by conduction and convection and IR.
"FAQs in Relation to Are Heat and Infrared the Same?
Are Heat and Infrared the Same?
No, heat and infrared are not the same. Heat is a form of energy transfer that occurs due to temperature differences between objects or substances, while infrared is a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. However, they are related as heat can generate infrared radiation.Is Infrared Light Also Called Heat?
Infrared light is not synonymous with heat; it’s a specific range within the electromagnetic spectrum. Although it’s often associated with warmth because it can cause heating when absorbed by an object, calling all types of infrared “heat” would be inaccurate.Is All Heat Radiation Infrared?
All thermal (heat) radiation falls under the category of infrared, but not every instance of heating involves this type of emission. In addition to radiative processes like those involving IR waves, there are conductive and convective methods for transferring thermal energy which don’t rely on electromagnetic emissions."Infrared does not heat the medium through which it travels but heats the surface of the target. infrared from the sun travels 93,000,000 miles through cold space and still heats the Earth.
so, I think that infrared radiation, as opposed to just heat, may trigger a response internally in the plant.
Another factor could be that incandescent is a smooth, unbroken curve transitioning the entire spectrum. perhaps hitting frequencies that the staccato-like led may omit.
also, the red/far-red ratio that causes the elongation response in veg and stretch may cause flower bulking in the flowering phase.
i still don't know for sure what caused the response or whether i can even repeat it but these factors may be responsible, individually or all together.
Instead of spotlights maybe you should use floods in your experiment.
I hate to be pedantic . . . but I will anyway
The term "heat" simply refers to the transfer of energy (or energy gradient) from an object with more kinetic energy to one with lower kinetic energy (Second Law of Thermodynamics).
Infra-red radiation causes "heat". So does every other form of electromagnetic radiation – including visible light and PAR. It is the RATE of energy transfer that we often think of as "heat" due to its rapid warming effect, but any rate of transfer between an object of higher kinetic energy to lower kinetic energy is "heat".
Energy is transferred one of three ways: via photons (electromagnetic waves), via conduction (a "hot" object touching a "colder" object), and via convection (air molecules warm up via conductive or radiative heat, then rise through the atmosphere transferring energy to whatever they come in contact with).
Standing in the sun you feel radiated energy as heat.
Touching a piece of metal warmed by the sun you feel conductive heat.
Standing in a warm current of air created by the sun you feel convective heat.
In a grow room, plants get their "warmth" from basically two sources: convective heat (ambient air temperature) and radiated heat (electromagnetic waves).
The reason infra-red photons feel "hotter" than visible light photons is due to the rate at which they impart their energy. IR imparts its energy faster and more completely than other photons because it interacts with matter more directly.
Here is a graph of radiation absorption by water. Radiation in the visible range mostly passes through water – which is why water is "transparent" – but other wavelengths are absorbed at a much more complete rate, including IR. Microwaves are at the right end of this scale (1mm-1000mm). Higher total absorption results in more total energy (heat) being transferred, which can feel "hotter".
Microwaves carry even less energy than IR, however microwaves have a special property that allows them to impart their energy on water molecules more effectively than other molecules, so a microwave oven will heat the water in food but not the ceramic cup or bowl that contains it. A convection oven – as the name suggests – will heat food and anything else that comes into contact with hot air. A heat lamp will also warm up any matter it's IR photons come into contact with, and not just water molecules.
Without confusing the issue, I included microwaves to show how lower energy photons can sometimes warm things (transfer energy) faster than higher energy photons. But I digress . . .
So really we're just talking about the mechanics of energy transfer.
The main difference between IR heat transfer and ambient (convective) heat transfer is the rate of transfer.
IR will transfer energy faster and deeper into the plant's cellular structure than convective heat. But apart from that they both have similar effects. (If you want a real head-fuck, you can start looking into the different vibrational models of water, which are all forms of kinetic energy but are the result of energy (heat) being imparted in slightly different ways.)
OK, we now know how heat (energy) is transferred. But what happens when temperatures stabilise?
When leaf temperatures stabilise with their surroundings, the leaf cannot get much "hotter" than the surrounding air (ambient temperature) because there is no heat (energy) gradient – in fact, the gradient starts to reverse. So any additional heat in the form of IR is absorbed before being released back into the atmosphere.
Plants release energy (heat) through convection (air passing over the leaf drawing heat away from the boundary layer) or via transpiration (opening of stomata to exchange warm gasses and vapourised water). Photosynthesis absorbs energy, and is thus endothermic. That's why PAR (photosynthetic active radiation in the visible spectrum) does not heat plants up as much as other forms of radiation (in addition to the fact water does not absorb other forms of radiation as well – and plants are mostly water).
And this is the reason I ask: does it make a difference where the "heat" comes from once a leaf reaches ambient temperature?
What advantage does radiative energy transfer provide over convective energy transfer? Does the vibrational model of a water molecule affect the speed and/or efficiency of that molecule to split in the light-dependent reactions of photosynthesis?
What is the advantage of providing more energy in the form of IR to a leaf that is already at optimal temperature and starts to over-transpire? Or worse, succumbs to photo-oxidative DNA damage, where the extra IR energy vibrates molecular bonds until they break?
Until someone can answer that, then personally I can't see what difference it makes where the heat comes from as long as the leaf is allowed to reach an optimal temperature for photosynthesis and other organic chemical reactions without inducing oxidative stress.
But by the same toke, my mind is not closed – so what sort of differences are you seeing with your experiments where you maintain similar PAR levels and RGB ratios, but increase the amount of IR – and not Far Red, which we know has photosynthetic and photomorphogenic properties?
Did you separate IR from FR? Did you maintain the same ambient temperatures? What about leaf temperatures?
Sorry, I know you've published this already but I don't know my way around here well enough yet to find it.
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Hey Arb. Different dog? Sad to see the bully goYou should drop in the ol farts thread prawn a lot of the old PG crew are in there.
arb says hello.
How's the censorship . . . er, I mean serenity around here these days? You know what I'm like. I'm not a troll, I was just built that way
exoticrobotic
Well-known member
All this led grow talk is surely fascinating and is ultimately leading to a 1000 diode array with 30 different freqs growing just one huge mushroom looking trichome.
Are we nearly there yet and do we still have to put up with the shitty looking leaves?
Are we nearly there yet and do we still have to put up with the shitty looking leaves?
You're confusing radiation wih energy transfer, heat radiation is not heat. And plants "know" that.I hate to be pedantic . . . but I will anyway
The term "heat" simply refers to the transfer of energy (or energy gradient) from an object with more kinetic energy to one with lower kinetic energy (Second Law of Thermodynamics).
Infra-red radiation causes "heat". So does every other form of electromagnetic radiation – including visible light and PAR. It is the RATE of energy transfer that we often think of as "heat" due to its rapid warming effect, but any rate of transfer between an object of higher kinetic energy to lower kinetic energy is "heat".
Energy is transferred one of three ways: via photons (electromagnetic waves), via conduction (a "hot" object touching a "colder" object), and via convection (air molecules warm up via conductive or radiative heat, then rise through the atmosphere transferring energy to whatever they come in contact with).
Standing in the sun you feel radiated energy as heat.
Touching a piece of metal warmed by the sun you feel conductive heat.
Standing in a warm current of air created by the sun you feel convective heat.
In a grow room, plants get their "warmth" from basically two sources: convective heat (ambient air temperature) and radiated heat (electromagnetic waves).
The reason infra-red photons feel "hotter" than visible light photons is due to the rate at which they impart their energy. IR imparts its energy faster and more completely than other photons because it interacts with matter more directly.
Here is a graph of radiation absorption by water. Radiation in the visible range mostly passes through water – which is why water is "transparent" – but other wavelengths are absorbed at a much more complete rate, including IR. Microwaves are at the right end of this scale (1mm-1000mm). Higher total absorption results in more total energy (heat) being transferred, which can feel "hotter".
View attachment 18940179
Microwaves carry even less energy than IR, however microwaves have a special property that allows them to impart their energy on water molecules more effectively than other molecules, so a microwave oven will heat the water in food but not the ceramic cup or bowl that contains it. A convection oven – as the name suggests – will heat food and anything else that comes into contact with hot air. A heat lamp will also warm up any matter it's IR photons come into contact with, and not just water molecules.
Without confusing the issue, I included microwaves to show how lower energy photons can sometimes warm things (transfer energy) faster than higher energy photons. But I digress . . .
So really we're just talking about the mechanics of energy transfer.
The main difference between IR heat transfer and ambient (convective) heat transfer is the rate of transfer.
IR will transfer energy faster and deeper into the plant's cellular structure than convective heat. But apart from that they both have similar effects. (If you want a real head-fuck, you can start looking into the different vibrational models of water, which are all forms of kinetic energy but are the result of energy (heat) being imparted in slightly different ways.)
OK, we now know how heat (energy) is transferred. But what happens when temperatures stabilise?
When leaf temperatures stabilise with their surroundings, the leaf cannot get much "hotter" than the surrounding air (ambient temperature) because there is no heat (energy) gradient – in fact, the gradient starts to reverse. So any additional heat in the form of IR is absorbed before being released back into the atmosphere.
Plants release energy (heat) through convection (air passing over the leaf drawing heat away from the boundary layer) or via transpiration (opening of stomata to exchange warm gasses and vapourised water). Photosynthesis absorbs energy, and is thus endothermic. That's why PAR (photosynthetic active radiation in the visible spectrum) does not heat plants up as much as other forms of radiation (in addition to the fact water does not absorb other forms of radiation as well – and plants are mostly water).
And this is the reason I ask: does it make a difference where the "heat" comes from once a leaf reaches ambient temperature?
What advantage does radiative energy transfer provide over convective energy transfer? Does the vibrational model of a water molecule affect the speed and/or efficiency of that molecule to split in the light-dependent reactions of photosynthesis?
What is the advantage of providing more energy in the form of IR to a leaf that is already at optimal temperature and starts to over-transpire? Or worse, succumbs to photo-oxidative DNA damage, where the extra IR energy vibrates molecular bonds until they break?
Until someone can answer that, then personally I can't see what difference it makes where the heat comes from as long as the leaf is allowed to reach an optimal temperature for photosynthesis and other organic chemical reactions without inducing oxidative stress.
But by the same toke, my mind is not closed – so what sort of differences are you seeing with your experiments where you maintain similar PAR levels and RGB ratios, but increase the amount of IR – and not Far Red, which we know has photosynthetic and photomorphogenic properties?
Did you separate IR from FR? Did you maintain the same ambient temperatures? What about leaf temperatures?
Sorry, I know you've published this already but I don't know my way around here well enough yet to find it.
I thought it was a really good explanation, but will add a couple of clarifications to points covered.
All forms of electromagnetic radiation, including infrared (IR) and visible light, can transfer energy and thus create a sensation of heat. However, the perception of heat depends not just on the rate of energy transfer but also on the specific wavelength’s interaction with matter. For example, IR radiation is readily absorbed by many materials, leading to a more noticeable heating effect.
Also, once a leaf reaches ambient temperature, the gradient for further heat transfer does diminish, however the type of heat source can still impact processes like transpiration and cellular stress.
All forms of electromagnetic radiation, including infrared (IR) and visible light, can transfer energy and thus create a sensation of heat. However, the perception of heat depends not just on the rate of energy transfer but also on the specific wavelength’s interaction with matter. For example, IR radiation is readily absorbed by many materials, leading to a more noticeable heating effect.
Also, once a leaf reaches ambient temperature, the gradient for further heat transfer does diminish, however the type of heat source can still impact processes like transpiration and cellular stress.
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Sorry mate, I'm not confusing anything. You need to look up the physics definition of "heat".
