[Chilly Willy]

ReikoX - Man, I don't even know what to say, lighting has come a long way. Your idea like you said allows a ton of manipulation. I just got off the Philips site on the section where they teach you about what all id going down in the latest in lighting and the first big thing that popped up was this big write up about how LED is cutting the edges in commercial lighting. This is a good area to visit if you have time, there are videos, articles, and workshops. I am really glad you came here and are sharing your excitement with what you have been learning about LED for grow ReikoX.

[Chilly Willy]

Philups has an amazing site to look through, there is even a section where you can read about trends, which include videos and all sorts of stuff. They also have a lot of charts and very detailed spec sheets for each bulb. I was just on there checking out ceramic metal halides. I like the fact that when they are on, others just think you have white lights on in your place. These metal halides of today even have some red spectrum in them, lighting has changed a lot over the years; I like these new ceramic bulbs.

If you guys want to see what all I was reading, come take a look later on in my photo album here. I will include the spec sheets, and spectrum charts, and footprint area covered. The specific bulb that I collected all this data for is the Philups CDM-T Elite 315W/942 PGZ18.1CT/12

[kelly1376]

You seem enough of a lighting enthusiast it would probably help you to learn about daily light integral, ppfd, umol, photons etc. Historically growers really only talked in terms of watts, but watts don't really mean anything, it's photon efficiency that matters. Watts in = photons out. Here's an interesting paper pay particular attention to pgs 5 & 6:

https://growershouse.com/images/PDFs...b__6441190.pdf

Good read on Par, PPFD:

https://fluence.science/science/par-ppf-ppfd-dli/

Good read on daily light integral:
https://www.extension.purdue.edu/ext...o/ho-238-w.pdf

Oh yeah and you will probably like this thread:

https://www.icmag.com/ic/showthread.php?t=293045

Some of the newer cob led setups have a photon efficiency over 2. I believe fluence does as well. Lots of folks been making their own cob lights check out timbergrowlights.com for some examples.

[ReikoX]

Thanks for the links Kelly. There is some very useful information in those papers.

[Chilly Willy]

Kelly1376 - you are I are on the same thoughts, I been reading all this material I grabbed, and it is talks about all of this more in depth. I also found some documented growths outside of our stuff that is really detailed, this showing the comparison of lights and the results in yield, distance between nodes.

Dude, I had no idea that the light spectrum chart was just a chunk of a bigger chart that includes so much stuff (for example radio frequency). That atoms wobble, tun over, and all these different ways atoms are affected, in turn other items perceive them (such as our eyes seeing light is done by one of those methods).

I been also reading how temperature, Co2, intensity, and wave length all take a role in the growth. Just Co2 alone when you amplify this that this is a different cycle in the plant than what is going on with the cycle in turning light into energy. That this guy did an experiment and found that light is what gives plants their mass and not the nutrients.

Also, some of these experiments show that it is not the HPS that gives the mass, it is the intensity. And that that a plant may only require a certain amount and this may even be a low amount in order for it take advantage of say the blue light. I mean this is really cool stuff.

You should go to the Wikipedia page on photosynthesis and after reading it, click on the links at the bottom. There are also some good links at the bottom of the Wiki page on Grow lighting. That is where I found some of the grow documents on other plants with all those details. Did you know that there are meters not to measure the photosynthesis but measure the Co2 synthesis which in turns tells you how well the plant is taking up light and using it. I say those meters on the internet and they were only around 350 bucks, they also had some that were around a couple grand.

I want to do my next grow using more science, and I am finding out be careful what you wish for (it may come true). It helps knowing the history and also helps knowing the history of bulbs. I been a this for the past two days. You inspired me to work harder Kelly, thanks again for that. hehehehe ... My buds just made a freind!

[Chilly Willy]

https://hortsci.ashspublications.org...2/374.full.pdf

Here is guy who grew potatoes indoors with three different grows using different types of light them measuring the node distance and mass of the dried product. He duplictaed his attempts and got the same results. It's very informative.

[Chilly Willy]

Jan van Helmont began the research of the process in the mid-17th century when he carefully measured the mass of the soil used by a plant and the mass of the plant as it grew. After noticing that the soil mass changed very little, he hypothesized that the mass of the growing plant must come from the water, the only substance he added to the potted plant. His hypothesis was partially accurate — much of the gained mass also comes from carbon dioxide as well as water. However, this was a signaling point to the idea that the bulk of a plant's biomass comes from the inputs of photosynthesis, not the soil itself.

Robert Emerson discovered two light reactions by testing plant productivity using different wavelengths of light. With the red alone, the light reactions were suppressed. When blue and red were combined, the output was much more substantial. Thus, there were two photosystems, one absorbing up to 600 nm wavelengths, the other up to 700 nm. The former is known as PSII, the latter is PSI. PSI contains only chlorophyll "a", PSII contains primarily chlorophyll "a" with most of the available chlorophyll "b", among other pigment. These include phycobilins, which are the red and blue pigments of red and blue algae respectively, and fucoxanthol for brown algae and diatoms. The process is most productive when the absorption of quanta are equal in both the PSII and PSI, assuring that input energy from the antenna complex is divided between the PSI and PSII system, which in turn powers the photochemistry.

Louis N.M. Duysens and Jan Amesz discovered that chlorophyll a will absorb one light, oxidize cytochrome f, chlorophyll a (and other pigments) will absorb another light, but will reduce this same oxidized cytochrome, stating the two light reactions are in series.

There are three main factors affecting photosynthesis and several corollary factors. The three main are:Light irradiance and wavelengthCarbon dioxide concentrationTemperature.

In the early 20th century, Frederick Blackman and Gabrielle Matthaei investigated the effects of light intensity (irradiance) and temperature on the rate of carbon assimilation. At constant temperature, the rate of carbon assimilation varies with irradiance, increasing as the irradiance increases, but reaching a plateau at higher irradiance. At low irradiance, increasing the temperature has little influence on the rate of carbon assimilation. At constant high irradiance, the rate of carbon assimilation increases as the temperature is increased. These two experiments illustrate several important points: First, it is known that, in general, photochemical reactions are not affected by temperature. However, these experiments clearly show that temperature affects the rate of carbon assimilation, so there must be two sets of reactions in the full process of carbon assimilation. These are, of course, the light-dependent 'photochemical' temperature-independent stage, and the light-independent, temperature-dependent stage. Second, Blackman's experiments illustrate the concept of limiting factors. Another limiting factor is the wavelength of light. Cyanobacteria, which reside several meters underwater, cannot receive the correct wavelengths required to cause photoinduced charge separation in conventional photosynthetic pigments. To combat this problem, a series of proteins with different pigments surround the reaction center. This unit is called a phycobilisome.

As carbon dioxide concentrations rise, the rate at which sugars are made by the light-independent reactions increases until limited by other factors. RuBisCO, the enzyme that captures carbon dioxide in the light-independent reactions, has a binding affinity for both carbon dioxide and oxygen. When the concentration of carbon dioxide is high, RuBisCO will fix carbon dioxide. However, if the carbon dioxide concentration is low, RuBisCO will bind oxygen instead of carbon dioxide. This process, called photorespiration, uses energy, but does not produce sugars.

RuBisCO oxygenase activity is disadvantageous to plants for several reasons: One product of oxygenase activity is phosphoglycolate (2 carbon) instead of 3-phosphoglycerate (3 carbon). Phosphoglycolate cannot be metabolized by the Calvin-Benson cycle and represents carbon lost from the cycle. 1) A high oxygenase activity, therefore, drains the sugars that are required to recycle ribulose 5-bisphosphate and for the continuation of the Calvin-Benson cycle. 2) Phosphoglycolate is quickly metabolized to glycolate that is toxic to a plant at a high concentration; it inhibits photosynthesis. 3) Salvaging glycolate is an energetically expensive process that uses the glycolate pathway, and only 75% of the carbon is returned to the Calvin-Benson cycle as 3-phosphoglycerate. The reactions also produce ammonia (NH3), which is able to diffuse out of the plant, leading to a loss of nitrogen.


Russian botanist Andrei Famintsyn was the first to use artificial light for plant growing and research (1868).

Output spectrum of a typical metal-halide lamp showing peaks at 385nm, 422nm, 497nm, 540nm, 564nm, 583nm (highest), 630nm, and 674nm.

According to the inverse-square law, the intensity of light radiating from a point source (in this case a bulb) that reaches a surface is inversely proportional to the square of the surface's distance from the source (if an object is twice as far away, it receives only a quarter the light) which is a serious hurdle for indoor growers, and many techniques are employed to use light as efficiently as possible. Reflectors are thus often used in the lights to maximize light efficiency. Plants or lights are moved as close together as possible so that they receive equal lighting and that all light coming from the lights falls on the plants rather than on the surrounding area.

With the introduction of ceramic metal halide lighting and full-spectrum metal halide lighting, they are increasingly being utilized as an exclusive source of light for both vegetative and reproductive growth stages.

If high-pressure sodium lights are used for the vegetative phase, plants grow slightly more quickly, but will have longer internodes, and may be longer overall.

Natural daylight has a high color temperature (approximately 5000-5800 K).

PAR designates the spectral range of solar radiation from 400 to 700 nanometers, which generally corresponds to the spectral range that photosynthetic organisms are able to use in the process of photosynthesis.

The irradiance of PAR can be expressed in units of energy flux (W/m2), which is relevant in energy-balance considerations for photosynthetic organisms. However, photosynthesis is a quantum process and the chemical reactions of photosynthesis are more dependent on the number of photons than the amount of energy contained in the photons.[39] Therefore, plant biologists often quantify PAR using the number of photons in the 400-700 nm range received by a surface for a specified amount of time, or the Photosynthetic Photon Flux Density (PPFD).[39] This is normally measured using mol m−2s−1.According to one manufacturer of grow lights, plants require at least light levels between 100 and 800 μmol m−2s−1.[40] For daylight-spectrum (5800 K) lamps, this would be equivalent to 5800 to 46,000 lm/m2.

Visible light lies toward the shorter end, with wavelengths from 400 to 700 nanometres.

For most of history, visible light was the only known part of the electromagnetic spectrum. The ancient Greeks recognized that light traveled in straight lines and studied some of its properties, including reflection and refraction. The study of light continued, and during the 16th and 17th centuries conflicting theories regarded light as either a wave or a particle.[6]The first discovery of electromagnetic radiation other than visible light came in 1800, when William Herschel discovered infrared radiation.[7] He was studying the temperature of different colors by moving a thermometer through light split by a prism. He noticed that the highest temperature was beyond red. He theorized that this temperature change was due to "calorific rays" that were a type of light ray that could not be seen.The next year, Johann Ritter, working at the other end of the spectrum, noticed what he called "chemical rays" (invisible light rays that induced certain chemical reactions). These behaved similarly to visible violet light rays, but were beyond them in the spectrum.[8] They were later renamed ultraviolet radiation.

There are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light). Radiation of each frequency and wavelength (or in each band) has a mix of properties of the two regions of the spectrum that bound it. For example, red light resembles infrared radiation in that it can excite and add energy to some chemical bonds and indeed must do so to power the chemical mechanisms responsible for photosynthesis and the working of the visual system.

The Sun emits its peak power in the visible region, although integrating the entire emission power spectrum through all wavelengths shows that the Sun emits slightly more infrared than visible light.

Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another. This action allows the chemical mechanisms that underlie human vision and plant photosynthesis. The light that excites the human visual system is a very small portion of the electromagnetic spectrum. A rainbow shows the optical (visible) part of the electromagnetic spectrum; infrared (if it could be seen) would be located just beyond the red side of the rainbow with ultraviolet appearing just beyond the violet end.

Electromagnetic radiation with a wavelength between 380 nm and 760 nm (400–790 terahertz) is detected by the human eye and perceived as visible light. Other wavelengths, especially near infrared (longer than 760 nm) and ultraviolet (shorter than 380 nm) are also sometimes referred to as light, especially when the visibility to humans is not relevant. White light is a combination of lights of different wavelengths in the visible spectrum. Passing white light through a prism splits it up into the several colors of light observed in the visible spectrum between 400 nm and 780 nm.

The behavior of EMR depends on its wavelength. Higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. When EMR interacts with single atoms and molecules, its behavior depends on the amount of energy per quantum it carries.EMR in the visible light region consists of quanta (called photons) that are at the lower end of the energies that are capable of causing electronic excitation within molecules, which leads to changes in the bonding or chemistry of the molecule.

In developmental biology, photomorphogenesis is light-mediated development, where plant growth patterns respond to the light spectrum. This is a completely separate process from photosynthesis where light is used as a source of energy. Phytochromes, cryptochromes, and phototropins are photochromic sensory receptors that restrict the photomorphogenic effect of light to the UV-A, UV-B, blue, and red portions of the electromagnetic spectrum.[1]The photomorphogenesis of plants is often studied by using tightly frequency-controlled light sources to grow the plants. There are at least three stages of plant development where photomorphogenesis occurs: seed germination, seedling development, and the switch from the vegetative to the flowering stage (photoperiodism).[2]

Typically, plants are responsive to wavelengths of light in the blue, red and far-red regions of the spectrum through the action of several different photosensory systems. The photoreceptors for red and far-red wavelengths are known as phytochromes. There are at least 5 members of the phytochrome family of photoreceptors. There are several blue light photoreceptors known as cryptochromes. The combination of phytochromes and cryptochromes mediate growth and the flowering of plants in response to red light, far-red light, and blue light.

Plants use phytochrome to detect and respond to red and far-red wavelengths. Phytochromes are signaling proteins that promote photomorphogenesis in response to red light and far-red light.[5] Phytochrome is the only known photoreceptor that absorbs light in the red/far red spectrum of light (600-750 nm) specifically and only for photosensory purposes.[1] Phytochromes are proteins with a light absorbing pigment attached called a chromophore. The chromophore is a linear tetrapyrrole called phytochromobilin.[6]There are two forms of phytochromes: red light absorbing, Pr, and far-red light absorbing, Pfr. Pfr, which is the active form of phytochromes, can be reverted to Pr, which is the inactive form, slowly by inducing darkness or more rapidly by irradiation by far-red light.[5] The phytochrome apoprotein, a protein that together with a prosthetic group forms a particular biochemical molecule such as a hormone or enzyme, is synthesized in the Pr form. Upon binding the chromophore, the holoprotein, an apoprotein combined with its prosthetic group, becomes sensitive to light. If it absorbs red light it will change conformation to the biologically active Pfr form.[5] The Pfr form can absorb far red light and switch back to the Pr form. The Pfr promotes and regulates photomorphogenesis in response to FR light, whereas Pr regulates de-etiolation in response to R light.[5]Most plants have multiple phytochromes encoded by different genes. The different forms of phytochrome control different responses but there is also redundancy so that in the absence of one phytochrome, another may take on the missing functions.[5] There are five genes that encode phytochromes in the Arabidopsis thaliana genetic model, PHYA-PHYE.[6] PHYA is involved in the regulation of photomorphogenesis in response to far-red light.[5] PHYB is involved in regulating photoreversible seed germination in response to red light. PHYC mediates the response between PHYA and PHYB. PHYD and PHYE mediate elongation of the internode and control the time in which the plant flowers.[6]Molecular analyses of phytochrome and phytochrome-like genes in higher plants (ferns, mosses, algae) and photosynthetic bacteria have shown that phytochromes evolved from prokaryotic photoreceptors that predated the origin of plants.

Plants contain multiple blue light photoreceptors which have different functions. Based on studies with action spectra, mutants and molecular analyses, it has been determined that higher plants contain at least 4, and probably 5, different blue light photoreceptors.Cryptochromes were the first blue light receptors to be isolated and characterized from any organism, and are responsible for the blue light reactions in photomorphogenesis.[6] The proteins use a flavin as a chromophore. The cryptochromes have evolved from microbial DNA-photolyase, an enzyme that carries out light-dependent repair of UV damaged DNA.[9] Two cryptochromes have been identified in plants. There are two different forms of crytochromes, CRY1 and CRY2, which regulate the inhibition of hypocotyl elongation in response to blue light.[9] Cryptochromes control stem elongation, leaf expansion, circadian rhythms and flowering time. In addition to blue light, cryptochromes also perceive long wavelength UV irradiation (UV-A).[9] Since the cryptochromes were discovered in plants, several labs have identified homologous genes and photoreceptors in a number of other organisms, including humans, mice and flies.[9]There are blue light photoreceptors that are not a part of photomorphogenesis. For example, phototropin is the blue light photoreceptor that controls phototropism.

Plants show various responses to UV light. UVR8 has been shown to be a UV-B receptor.[10]

In plants, cryptochromes mediate phototropism, or directional growth toward a light source, in response to blue light. This response is now known to have its own set of photoreceptors, the phototropins.Unlike phytochromes and phototropins, cryptochromes are not kinases. Their flavin chromophore is reduced by light and transported into the cell nucleus, where it affects the turgor pressure and causes subsequent stem elongation. To be specific, Cry2 is responsible for blue-light-mediated cotyledon and leaf expansion. Cry2 overexpression in transgenic plants increases blue-light-stimulated cotyledon expansion, which results in many broad leaves and no flowers rather than a few primary leaves with a flower.[18] A double loss-of-function mutation in Arabidopsis thaliana Early Flowering 3 (elf3) and Cry2 genes delays flowering under continuous light and was shown to accelerate it during long and short days, which suggests that Arabidopsis CRY2 may play a role in accelerating flowering time during continuous light.[19]

Cryptochromes receptors cause plants to respond to blue light via photomorphogenesis. Cryptochromes help control seed and seedling development, as well as the switch from the vegetative to the flowering stage of development. In Arabidopsis, it is shown that cryptochromes controls plant growth during sub-optimal blue-light conditions.[21]


Phytochrome is a photoreceptor and a pigment that plants, and some animals, use to detect light. It is sensitive to light in the red and far-red region of the visible spectrum. Many flowering plants use it to regulate the time of flowering based on the length of day and night (photoperiodism) and to set circadian rhythms. It also regulates other responses including the germination of seeds (photoblasty), elongation of seedlings, the size, shape and number of leaves, the synthesis of chlorophyll, and the straightening of the epicotyl or hypocotyl hook of dicot seedlings. It is found in the leaves of most plants.

Phytochrome consists of two identical chains (A and B). Each chain has a PAS domain and GAF domain. The PAS domain serves as a signal sensor and the GAF domain is responsible for binding to cGMP and also senses light signals. Together, these subunits form the phytochrome region, which regulates physiological changes in plants to changes in red and far red light conditions. In plants, red light changes phytochrome to its biologically active form, while far red light changes the protein to its biologically inactive form.

Phytochromes are characterised by a red/far-red photochromicity. Photochromic pigments change their "colour" (spectral absorbance properties) upon light absorption. In the case of phytochrome the ground state is Pr, the r indicating that it absorbs red light particularly strongly. The absorbance maximum is a sharp peak 650–670 nm, so concentrated phytochrome solutions look turquoise-blue to the human eye. But once a red photon has been absorbed, the pigment undergoes a rapid conformational change to form the Pfr state. Here fr indicates that now not red but far-red (also called "near infra-red"; 705–740 nm) is preferentially absorbed. This shift in absorbance is apparent to the human eye as a slightly more greenish colour. When Pfr absorbs far-red light it is converted back to Pr. Hence, red light makes Pfr, far-red light makes Pr. In plants at least Pfr is the physiologically active or "signalling" state.

Around 1989, several laboratories were successful in producing transgenic plants which produced elevated amounts of different phytochromes (overexpression). In all cases the resulting plants had conspicuously short stems and dark green leaves. Harry Smith and co-workers at Leicester University in England showed that by increasing the expression level of phytochrome A (which responds to far-red light), shade avoidance responses can be altered.[5] As a result, plants can expend less energy on growing as tall as possible and have more resources for growing seeds and expanding their root systems. This could have many practical benefits: for example, grass blades that would grow more slowly than regular grass would not require mowing as frequently, or crop plants might transfer more energy to the grain instead of growing taller.

[Chilly Willy]

I went through a chain of wikipedia pages, one leading to another; those are what I copied and pasted from there. .... Nudge ... wake up! hehehehe

I wanted to learn more about what is going on with lighting. Vendors try to sell the latest mouse trap and I just to make sure it is going to catch something before I buy it. It would be nice to have an efficient lighting system. It's the last detail.

The strain, grow medium, containers, nutrients, Co2, air exchange, drying & cure are all already dialed in. (back flip, and another and then a big smile).

[kelly1376]

The most efficient setups are gonna be cob setups or double ended HPS like gavitas. Gavitas are over 40% efficient and just damn powerful at +1000 watts and ~2100 umol output per lamp. To duplicate that with other setups would cost a lot. I kinda like your original dual bulb setup in the OP though. I suppose you could duplicate that with cobs you could build something similar to this with different kelvin temp:

https://timbergrowlights.com/100-watt...ear-framework/

Put 2 side by side and run a 5000k on one side and a 2500k on the other.

[positivity]

Originally Posted by kelly1376

The most efficient setups are gonna be cob setups or double ended HPS like gavitas. Gavitas are over 40% efficient and just damn powerful at +1000 watts and ~2100 umol output per lamp. To duplicate that with other setups would cost a lot. I kinda like your original dual bulb setup in the OP though. I suppose you could duplicate that with cobs you could build something similar to this with different kelvin temp:

https://timbergrowlights.com/100-wat...ear-framework/

Put 2 side by side and run a 5000k on one side and a 2500k on the other.

Timber

1. Copied lights i was building to instigate a fight

2. Originally optic selling bottom of the barrel reseller lights from China

3. Now sells parts with a plug installed at a markup

4. Ad campaign everywhere and anywhere

5. Followers, probably workers, instigating fights

6. Their first light was in a tool box that over heated with customers not getting any response


Hello timber or fluence. Whoever you are

Not recommended. Check out gayapex for cob lights. Straight from Asia and fully built with what looks like decent features.

The Ursa or starlight? that advertises here looks like one of the better leds also.

I'd say your on the right path with cmh. Let led grow up

I could expand on that, meh, not worth the time
2 cents

They can't even respect the path your on...