LED Growers Unite, Who makes the BEST LED and how long has it lasted ? Cast Your Vote!!!

[acespicoli]

ANYONE PLAYING AROUND WITH THESE ?

How to convert from fluorescent lights to LED​

This primer offers helpful information for updating your lighting from fluorescent fixtures to LED tubes.
By
Dave Mowitz
Dave Mowitz
In 1982 Dave came to Successful Farming as a senior editor first covering agronomic topics and then machinery. He went on to serve the nation’s farmers as executive editor of Successful Farming Magazine and editor of the Ageless Iron Almanac, a bimonthly publication covering the hobby of agricultural collectibles. Dave recently retired from the Successful Farming family but continues to serve the organization as a contributing editor.
SUCCESSFUL FARMING’S EDITORIAL GUIDELINES

Updated on April 24, 2024

PHOTO: KURT SCHULTZ
Converting building lights to LED bulbs to cash in on their superior light, lower electricity consumption, and much longer life is easy when it comes to screw-in bulbs. This is due to the fact that LED bulbs readily fit into the same screw-in sockets used by incandescent and CFL (compact fluorescents) bulbs, both of which are growing scarce on store shelves.

Converting fluorescent fixtures to accommodate LED tubes is more complicated. Not all fluorescent fixtures are designed the same. There is also a lot of confusing information being offered about LED conversions.

One thing is sure: You can change fluorescent fixtures over to LED one fixture at a time. That allows you to upgrade lighting on a schedule that fits your pocketbook.

If you are resistant to upgrading to LED bulbs, bear in mind that both bulbs and ballasts for T12 fluorescent fixtures are growing rare and are getting increasingly more difficult to find. T8 bulbs and ballasts are on the same chopping block in the near future. At this point, no termination of T5 bulbs and fixtures is scheduled, but this fluorescent fixture is targeted to be discontinued in the future.

Convert existing fixtures to instant fit​

There is a wide variety of methods for converting to LED tubes. The simplest is to completely replace old fluorescent fixtures with brand-new LED fixtures. However, LED fixtures to replace four-bulb (8-foot-long) fluorescent fixtures (common in farm buildings) can set you back $100 or more per unit.

Instead, there are numerous ways to convert an existing fluorescent fixture to accept LED tubes. Such tubes are officially designated as UL Type A and are sold under descriptions like instant fit, plug-and-play, and remote driver lamps.

“These products are designed to be installed directly into an existing fixture without having to modify the fixture,” says John Hynek, formerly of Philips Lighting. “We do recommend that if the ballast in the existing fixture is 5 to 7 years old that you replace the ballast when installing the new bulbs.”

Ballast bypass conversion​

Another option is to modify your existing fluorescent fixtures to accept UL Type B tubes, which are commonly sold as ballast bypass or direct wire bulbs. This requires that the fixture be rewired to bypass the ballast, which can either be left in place or removed. “We highly recommend if the fixture is rewired that it be labeled to show it can only use UL Type B bulbs,” Hynek urges.

The advantage of going with ballast bypass tubes is that you won’t need to replace older ballasts. This can save you money in new ballast costs. Be sure to check that the ballast bypass tubes you are buying come with an installation wiring schematic, as the chore can vary whether the tube is a one-side or one-end tube vs. a two-side or two-end tube.

Hynek says ballast bypass tubes are more expensive than instant-fit tubes, but that difference depends on your existing fixtures’ needs.

Ballast bypass bulbs are priced around $7 to $74 each, depending on their light output. For example, a four-pack of 8,000-lumen, 40-watt, 8-foot-long LED bulbs sell for $51.43 per pack. These prices go up depending on bulb quality.

In comparison, the cost of instant-fit LED tubes is 25% less than that of ballast bypass tubes, Hynek says.

Before committing to either tube type when converting existing fluorescent fixtures, the lighting industry highly recommends that you talk to your lighting supplier about your intentions to change the tubes on old fluorescent fixtures.

To do that, gather the operating performance information about your old fixture (it should be printed inside the fixture) and take that to your supplier to discuss the options.

“A reputable supplier can take that information and guide you to a retrofit tube that fits your needs,” Hynek points out.

Also, Philips offers a website that provides a wealth of information about the differences.

Finally, be sure to check with your local electrical supplier to see if it offers rebates for converting to LED bulbs so you can cash in on this incentive.

One-end vs. two-end ballast bypass tubes​

Converting to ballast bypass tubes presents two challenges. First, the industry offers both single-end and double-end bulbs. Some fixtures may not have the correct socket (sometimes called tombstones) to accommodate ballast bypass tubes.

Regarding tube differences, with a single-end bulb, all the wiring goes to the sockets at one end of the fixture. The sockets at the other end of the fixture are left unwired.

With a double-end bulb, you wire the supply (hot) wire (typically a black or a red wire) to the sockets at one end of the bulb and the neutral wire (typically a white wire) to the sockets at the other end of the bulb. In a two- or four-bulb fixture conversion, you would wire all the sockets at one end of the fixture to the supply wire and all the sockets at the other end of the fixture to the neutral wire in a series. “We have found that rewiring for double-end tubes takes 25% less time than wiring for single-end LED tubes,” Hynek says.

Different sockets​

The other complication with converting a fluorescent tube fixture involves the type of socket that the existing fixture currently uses. LED tubes require nonshunted sockets. Fluorescent fixtures can either have shunted or nonshunted sockets. The illustration below displays the differences between the two.

• Shunted sockets receive voltage through a single set of wires and spread it to both contacts.
• In nonshunted sockets, the contacts inside the socket are separate from each other.

Typically, older T12 fluorescent tubes use nonshunted sockets. T8 and T5 fixtures that employ rapid-start, programmed-start, or dimming ballasts typically use nonshunted tombstones.

T8 and T5 fixtures with instant-start ballasts use shunted tombstones.

To know for certain which socket is in use in your fixture, use a volt-ohm meter to determine whether the sockets are shunted or nonshunted.

To do this, turn the power off to your fixture. Next, turn your VOM dial to the continuity setting. Place a contact point on each side of the socket. The VOM will light up, ring, or beep if the socket is shunted.

The good news is that replacement nonshunted sockets are fairly cheap. Nonshunted tombstones range from 69¢ to $1 per socket online.

How to convert from fluorescent lights to LED

This primer offers helpful information for updating your lighting from fluorescent fixtures to LED tubes.

www.agriculture.com

 

[Ca++]

7 weeks plants, I have had a fair few. Working my way through many that remotely fitted the bill. I just did a fast version 6 week green poison, and while it wasn't a keeper, it did finish in good time. It wouldn't be a bad start, to a week of trimming them in order. What I learned was to find the 7 weeker in the standard green poison. I don't need the fast.

I like the 11 roses fv, and the killer kush fv is good. I'm mixing 7 or 8 weekers now, to get my trimming done over a week. It's all scheduling, if you want a serious turnover. There are plenty of 8 week plants (and less) testing well at cups. Pulling down good number. Doing the doo, without a long term bloom.

I really can't take people seriously, when they don't know how many weeks they have been in flower, and it's always going to be another week or two. The same people sit weeks with empty rooms, and no matter how big a house, they never make any more money. The professional approach is to make money. Which means working your space to the maximum. If I'm on a 7 week rota, using plants that should be done at 7 weeks. They are coming down at 7 weeks. They can't have another week, as that is 15% longer, and they won't do 15% more. They have failed, and the run ends there. Nothing can stop the train, and the train should plan for such losses in it's expected results. Never keep a bad crop growing, because it's bad, and you should have a good one ready to replace it. Which will go bad waiting. A new plant should be a small proportion of the grow anyway, and early bud isn't worthless. We have to be demanding, to keep such a rota. It's 7 and a half crops a year, so loosing even an entire one, isn't that painful.

 

[Ca++]

shizer

 

[acespicoli]

Some manufacturers are adding an extremely efficient red spectrum led to their builds they are in ths high 3+/j this is bumping the entire build ppf to unrealistic paramaters when viewed in comparison to full spectrum white light led efficiency... Misleading advertising, or does the plant really benefit from the added red in flower ?

Also which end of the light spectrum adds to the largest yields? When were talking total photons what exact spectrum sends the most energy?

Target photosynthesis or provide full spectrum?

 

[Rocket Soul]

Some manufacturers are adding an extremely efficient red spectrum led to their builds they are in ths high 3+/j this is bumping the entire build ppf to unrealistic paramaters when viewed in comparison to full spectrum white light led efficiency... Misleading advertising, or does the plant really benefit from the added red in flower ?

Also which end of the light spectrum adds to the largest yields? When were talking total photons what exact spectrum sends the most energy?

Target photosynthesis or provide full spectrum?

Why not both? Try to achieve a compromise between highest light/photosynthetic levels and best cannabis flowering expression?
To do this is not the easiest since you dont have any way around having to do practical tests, several runs of side by sides with several genetics. But there is plenty to indicate where to start looking:

Frontiers | The role of red and white light in optimizing growth and accumulation of plant specialized metabolites at two light intensities in medical cannabis (Cannabis sativa L.)

The cultivation of medical cannabis (Cannabis sativa L.) is expanding in controlled environments, driven by evolving governmental regulations for healthcare ...

www.frontiersin.org

Not sure if i posted this one before. It studies yield and a bunch of other items of diffrent spectrums. best performer was a wide red supplement (rather than only 660nm red) hitting both chloropeaks in the red end : better yield and what seems like better quality, especially as intensity increased.

Yield: to my best understanding its down to two different things: how strong the flower response is, based around red spectrum % and composition, and somewhat inhibited by blue. And then general density; determined by green amount %, more green: harder but less appealing buds. This last thing is my own opinion, dont have more than anecdotal on it but it aligns well both with yield results and science around "plant green response" - more fiber, more stick type growth rather than more lush but softer buds. But then i ask why are you trying to grow more stick just for yield? Its just the same buds but with more fibres in them so if they yield more weight they dont yield more bud or flower materials and metabolites. At least good enough for me for a working hypothesis.


Obviously i only talk about light/spectrum, there are many other things that will affect both density and flower response, genetics etc

 

[Rocket Soul]

Target photosynthesis or provide full spectrum?

Once your light is somewhere above 2.5 ppf/w it may just be better to focus on a kickass spectrum and just add a little more power to get the best yield/quality. To make up from 2.75 all you would have to go up 10% in watts to get the same output. Its better to be generous with both intensity and spectrum.
Next build ill target 40w/square foot with some different spectrums to figure out what type of red supplement i like better.

 

[acespicoli]

Light quality refers to the spectral distribution of light given to a plant. Light quality is grouped into colors based on wavelength; 320-400 nanometers (nm) is UVA, 400-500 nm is blue, 500-600 nm is green, 600-700 nm is red, and 700-750 nm is far red, sometimes referred to as near-infrared. Light quality can also be expressed as ratios, e.g. 3:2 red:blue ratio, or sometimes as their peak irradiance, e.g. 450 nm blue light and 660 nm red light. Photomorphogenesis is the term for light-mediated plant responses to light spectrum. Plants are able to sense parts of the electromagnetic spectrum through a network of photoreceptors including phytochromes, cryptochromes, phototropin, and zeiltupe. Each receptor is able to sense different parts of the electromagnetic spectrum. Information about the light spectrum can affect seed germination, the signal to transition from vegetative to flowering, and the production of secondary metabolites such as anthocyanins.[40]

Grow light - Wikipedia

en.wikipedia.org

Yeah thats what I was looking for that kinda data

just had a dejavu moment this is DIY gold

Frontiers | The role of red and white light in optimizing growth and accumulation of plant specialized metabolites at two light intensities in medical cannabis (Cannabis sativa L.)

The cultivation of medical cannabis (Cannabis sativa L.) is expanding in controlled environments, driven by evolving governmental regulations for healthcare ...

www.frontiersin.org

Conclusions​

Our study revealed an interaction between spectrum and PPFD on plant dry matter production and inflorescence yield of medical cannabis. White light with a dual red peak at 640 and 660 nm, compared to white light with a single red peak at 660 nm, increased inflorescence yield and light use efficiency, regardless of PPFD. This increase was primarily due to increased total plant dry matter production and a more open plant architecture, which may have improved photon capture. White fraction and spectrum broadness had no effect on inflorescence yield, irrespective of PPFD. There was no treatment effect on total cannabinoid concentrations, which indicates a promising potential for maintaining consistent quality in terms of PSM. However, at higher PPFD, white light with a dual red peak of 640 and 660 nm compared to white light with a single red peak at 660 nm increased terpenoid concentrations. At low PPFD, photosynthetic parameters like maximum photosynthetic rate and quantum yield were increased when grown under white light with a dual red peak of 640 and 660 nm compared to white light with a single red peak at 660 nm, while spectrum had no effect at higher PPFD. The addition of 640 nm alongside 660 nm shows potential in improving light use efficiency and promoting plant dry matter production.

Plant growth analysis - Wikipedia

en.wikipedia.org

https://en.wikipedia.org/wiki/Relative_growth_rate
Yeah frontiers rocks @Rocket Soul
White light with a dual red peak at 640 and 660 nm

 

[acespicoli]

Photomorphogenesis - Wikipedia

en.m.wikipedia.org

Light receptors for photomorphogenesis
edit

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.
Red/far-red light
edit

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.[6] 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.[7]

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.[6] 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.[6] 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.[6]

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.[6] There are five genes that encode phytochromes in the Arabidopsis thaliana genetic model, PHYA-PHYE.[7] PHYA is involved in the regulation of photomorphogenesis in response to far-red light.[6] 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.[7]

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.[4]

Takuma Tanada observed that the root tips of barley adhered to the sides of a beaker with a negatively charged surface after being treated with red light, yet released after being exposed to far-red light.[8] For mung bean it was the opposite, where far-red light exposure caused the root tips to adhere, and red light caused the roots to detach.[9] This effect of red and far-red light on root tips is now known as the Tanada effect.
Blue light
edit

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.[7] 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.[10] There are two different forms of cryptochromes that have been identified in plants, CRY1 and CRY2, which regulate the inhibition of hypocotyl elongation in response to blue light.[10] 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).[10] 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.[10]

There are blue light photoreceptors that are not a part of photomorphogenesis. For example, phototropin is the blue light photoreceptor that controls phototropism.
UV light
edit

Plants show various responses to UV light. UVR8 has been shown to be a UV-B receptor.[11] Plants undergo distinct photomorphogenic changes as a result of UV-B radiation. They have photoreceptors that initiate morphogenetic changes in the plant embryo (hypocotyl, epicotyl, radicle)[12] Exposure to UV- light in plants mediates biochemical pathways, photosynthesis, plant growth and many other processes essential to plant development. The UV-B photoreceptor, UV Resistance Locus8 (UVR8) detects UV-B rays and elicits photomorphogenic responses. These response are important for initiating hypocotyl elongation, leaf expansion, biosynthesis of flavonoids and many other important processes that affect the root-shoot system.[13] Exposure to UV-B rays can be damaging to DNA inside of the plant cells, however, UVR8 induces genes required to acclimate plants to UV-B radiation, these genes are responsible for many biosynthesis pathways that involve protection from UV damage, oxidative stress, and photorepair of DNA damage.[14]

There is still much to be discovered about the mechanisms involved in UV-B radiation and UVR8. Scientists are working to understand the pathways responsible for plant UV receptors response to solar radiation in natural environments.[14]

 

[acespicoli]

Guess that is a good explanation for the success of blurple lights, and why to add extra reds at different nm wavelengths

 

[acespicoli]

Yield photon flux​

edit
Weighting factor for photosynthesis. The photon-weighted curve is for converting PPF to YPF; the energy-weighted curve is for weighting PAR expressed in watts or joules.
There are two common measures of photosynthetically active radiation: photosynthetic photon flux (PPF) and yield photon flux (YPF). PPF values all photons from 400 to 700 nm equally, while YPF weights photons in the range from 360 to 760 nm based on a plant's photosynthetic response.[8]

PAR as described with PPF does not distinguish between different wavelengths between 400 and 700 nm, and assumes that wavelengths outside this range have zero photosynthetic action. If the exact spectrum of the light is known, the photosynthetic photon flux density (PPFD) values in μmol⋅s−1⋅m−2) can be modified by applying different weighting factors to different wavelengths. This results in a quantity called the yield photon flux (YPF).[8] The red curve in the graph shows that photons around 610 nm (orange-red) have the highest amount of photosynthesis per photon. However, because short-wavelength photons carry more energy per photon, the maximum amount of photosynthesis per incident unit of energy is at a longer wavelength, around 650 nm (deep red).

It has been noted that there is considerable misunderstanding over the effect of light quality on plant growth. Many manufacturers claim significantly increased plant growth due to light quality (high YPF). The YPF curve indicates that orange and red photons between 600 and 630 nm can result in 20 to 30% more photosynthesis than blue or cyan photons between 400 and 540 nm. [9][10] But the YPF curve was developed from short-term measurements made on single leaves in low light. More recent longer-term studies with whole plants in higher light indicate that light quality may have a smaller effect on plant growth rate than light quantity. Blue light, while not delivering as many photons per joule, encourages leaf growth and affects other outcomes.[9][11]

The conversion between energy-based PAR and photon-based PAR depends on the spectrum of the light source (see Photosynthetic efficiency).


This leaves us with more questions maybe, but which is the best led to have ?

 

[acespicoli]

Photosynthetic efficiency - Wikipedia

en.m.wikipedia.org

Starting with the solar spectrum falling on a leaf,

47% lost due to photons outside the 400–700 nm active range (chlorophyll uses photons between 400 and 700 nm, extracting the energy of one 700 nm photon from each one)
30% of the in-band photons are lost due to incomplete absorption or photons hitting components other than chloroplasts
24% of the absorbed photon energy is lost due to degrading short wavelength photons to the 700 nm energy level
68% of the used energy is lost in conversion into d-glucose
35–45% of the glucose is consumed by the leaf in the processes of dark and photo respiration

Stated another way:

100% sunlight → non-bioavailable photons waste is 47%, leaving
53% (in the 400–700 nm range) → 30% of photons are lost due to incomplete absorption, leaving
37% (absorbed photon energy) → 24% is lost due to wavelength-mismatch degradation to 700 nm energy, leaving
28.2% (sunlight energy collected by chlorophyll) → 68% is lost in conversion of ATP and NADPH to d-glucose, leaving
9% (collected as sugar) → 35–40% of sugar is recycled/consumed by the leaf in dark and photo-respiration, leaving
5.4% net leaf efficiency.

Many plants lose much of the remaining energy on growing roots. Most crop plants store ~0.25% to 0.5% of the sunlight in the product (corn kernels, potato starch, etc.).

 

[Rocket Soul]

Guess that is a good explanation for the success of blurple lights, and why to add extra reds at different nm wavelengths

Yes, but we still dont quite know which nm are more important. If we should try for chloropeaks or the action spectrum of the phytochrome; they are not quite the same. Or even shot for a perfect emmerson effect?

Even the study above didnt give completely "clean" results. So the 640/660 condition worked better than the rest. But it also has the condition of 630-640>660nm in intensity. How do we know its the boost and not the slope in the spectrum?

Nowhere have i seen proper studies done on adding 680nm with leds.

We have to do this work ourselves if we want it done right

 

[acespicoli]

The other issue is strain dependant results
So yeah definately have to dial your room/plant

 

[acespicoli]

What % of the photons at what spectrum arent wasted ...? Going to add the DLI day length integer calc here for led grows, and compare to solar latitudes around the globe

 

[acespicoli]

Economic Analysis of Greenhouse Lighting:​

Light Emitting Diodes vs. High Intensity Discharge Fixtures​

Published: June 6, 2014

• https://doi.org/10.1371/journal.pone.0099010

A lot has hanged in 10 years...

 

[acespicoli]

Figure 2. Absorbance spectra of photoreceptors. Spectrum data are derived from Taiz and Zeiger (2002), Galvão and Fankhauser (2015), and Sager et al. (1988).

Front. Plant Sci., 28 March 2019
Sec. Crop and Product Physiology
Volume 10 - 2019 | https://doi.org/10.3389/fpls.2019.00296

 

[acespicoli]

Carotenoid - Wikipedia

en.wikipedia.org

Photophysics​

The length of the multiple conjugated double bonds determines their color and photophysics.[9][10] After absorbing a photon, the carotenoid transfers its excited electron to chlorophyll for use in photosynthesis.[9] Upon absorption of light, carotenoids transfer excitation energy to and from chlorophyll. The singlet-singlet energy transfer is a lower energy state transfer and is used during photosynthesis.[7] The triplet-triplet transfer is a higher energy state and is essential in photoprotection.[7] Light produces damaging species during photosynthesis, with the most damaging being reactive oxygen species (ROS).[11] As these high energy ROS are produced in the chlorophyll the energy is transferred to the carotenoid’s polyene tail and undergoes a series of reactions in which electrons are moved between the carotenoid bonds in order to find the most balanced (lowest energy) state for the carotenoid.[9]

Carotenoids defend plants against singlet oxygen, by both energy transfer and by chemical reactions. They also protect plants by quenching triplet chlorophyll.[12] By protecting lipids from free-radical damage, which generate charged lipid peroxides and other oxidised derivatives, carotenoids support crystalline architecture and hydrophobicity of lipoproteins and cellular lipid structures, hence oxygen solubility and its diffusion therein.[13]

Phytochemistry is the study of phytochemicals, which are chemicals derived from plants. Phytochemists strive to describe the structures of the large number of secondary metabolites found in plants, the functions of these compounds in human and plant biology, and the biosynthesis of these compounds. Plants synthesize phytochemicals for many reasons, including to protect themselves against insect attacks and plant diseases. The compounds found in plants are of many kinds, but most can be grouped into four major biosynthetic classes: alkaloids, phenylpropanoids, polyketides, and terpenoids.

Phytochemistry can be considered a subfield of botany or chemistry. Activities can be led in botanical gardens or in the wild with the aid of ethnobotany. Phytochemical studies directed toward human (i.e. drug discovery) use may fall under the discipline of pharmacognosy, whereas phytochemical studies focused on the ecological functions and evolution of phytochemicals likely fall under the discipline of chemical ecology. Phytochemistry also has relevance to the field of plant physiology.

Photochemistry - Wikipedia

en.wikipedia.org

 

[kro-magnon]

I have used LED for 18 months only and only 2 brands, in veg I have a small Mars Hydro 100w, in flo a Lumatek 465w. I am very happy with the results I get from the Lumatek but I know I can do better yet, I've made a bit over 1G/W , I know I can get up to 1,5 G/W if I can get everything else run perfectly. I can't compare the results I get from my Lumatek to other LED brands yet and very few growers around me have some different brands. I had my light with a good discount,750€ instead of 1000€ but it is an expensive brand, the investment is quickly paid back thanks to higher yields and better quality compared to HPS(only light I can compare).
The Mars Hydro in veg is doing a goos job as well, the plants are healthier and squatter than the ones I had with my HPS or MH 150w, only exception would be the Philips MH 150W, it is to this day the best veg light I've had, making plants who could yield more than 100g after only 5 weeks of 18/6, too bad they discountinued them because only cannabis growers were buying them. But I'm not sure I would but again a Mars Hydro, there is better option on the market for vegging.
There is one brand doing LED I'm curious about, it is Adjust A Wing, we all know their reflectors and DE HPS but they also have a Helion LED line; I've not seen anyone using them yet, they are very expensive but knowing the quality of the products from this brand it's possible they worth the high price, if someone has used them please give some feedback.
The DIY option is great when you have the knowledge and tools to make the projects but it is not given to everybody, I can't remember when I have welded or solded(don't know what the goos verb is) an element on a electric circuit for the last time, it was decades ago.

 

[kro-magnon]

7 weeks plants, I have had a fair few. Working my way through many that remotely fitted the bill. I just did a fast version 6 week green poison, and while it wasn't a keeper, it did finish in good time. It wouldn't be a bad start, to a week of trimming them in order. What I learned was to find the 7 weeker in the standard green poison. I don't need the fast.

I like the 11 roses fv, and the killer kush fv is good. I'm mixing 7 or 8 weekers now, to get my trimming done over a week. It's all scheduling, if you want a serious turnover. There are plenty of 8 week plants (and less) testing well at cups. Pulling down good number. Doing the doo, without a long term bloom.

I really can't take people seriously, when they don't know how many weeks they have been in flower, and it's always going to be another week or two. The same people sit weeks with empty rooms, and no matter how big a house, they never make any more money. The professional approach is to make money. Which means working your space to the maximum. If I'm on a 7 week rota, using plants that should be done at 7 weeks. They are coming down at 7 weeks. They can't have another week, as that is 15% longer, and they won't do 15% more. They have failed, and the run ends there. Nothing can stop the train, and the train should plan for such losses in it's expected results. Never keep a bad crop growing, because it's bad, and you should have a good one ready to replace it. Which will go bad waiting. A new plant should be a small proportion of the grow anyway, and early bud isn't worthless. We have to be demanding, to keep such a rota. It's 7 and a half crops a year, so loosing even an entire one, isn't that painful.

Personally I organise my cycles by 10 weeks because I like to have several types of high, in my plants I have some 7/8 weekers, 9, 10/11 weekers. If use 2 different strategies to have my room filled to the max all the time, I replace each harvested plant by a new one from veg or I wait to harvest all the plants and give a bit more veg time under my bigger light. It depends on the plants growth in veg but my goal is to use each square centimer of my grow area to the max as I grow in an illegal country and have a very small scale grow.
In a year I do 5 harvests of 400/500g, for the space used (0,6 m2 veg/ 1,4m2 flo) I'm pretty happy with my annual yield but I hope to increase to 600g by harvest, I know it's possible with the good environment and more important the good plants because today there is a lot of cross who produce high quality buds with under average yield.

 

[Ca++]

Personally I organise my cycles by 10 weeks because I like to have several types of high, in my plants I have some 7/8 weekers, 9, 10/11 weekers. If use 2 different strategies to have my room filled to the max all the time, I replace each harvested plant by a new one from veg or I wait to harvest all the plants and give a bit more veg time under my bigger light. It depends on the plants growth in veg but my goal is to use each square centimer of my grow area to the max as I grow in an illegal country and have a very small scale grow.
In a year I do 5 harvests of 400/500g, for the space used (0,6 m2 veg/ 1,4m2 flo) I'm pretty happy with my annual yield but I hope to increase to 600g by harvest, I know it's possible with the good environment and more important the good plants because today there is a lot of cross who produce high quality buds with under average yield.

You could certainly increase the yield, but prioritising it might mean doing plants you are not so keen on. That GP fast looked capable of 400-500g per meter, and didn't need 7 weeks. So you are talking 8 crops a year if you just cycle already vegged plants, through a constant 12 hour space. I don't see a problem doing 4kg a meter, per year, counting just the flower space.

I' not sure if that's a 1.2 tent, giving 1.44sqm or a 1.4 giving 2sqm. That's 6-8kg a year. You would be working the shit out of it though, and accepting the compromise of fast plants.

I don't find speed is really that defining, in terms of the products effect. The general fact is, a sativa buzz achieved over 16 weeks isn't happening. However, there isn't a time constraint I know of, that says certain compounds need 8 weeks or more. Only degradation products come to mind. Which are 100% necessary no doubt. However, the acid forms of compounds can be abundant in a few weeks, and degradation can happen during a cure. It's not a science I can really address, but I have 7 week plants that can silence anybody, and others that can lift people into orbit. There is no issue of tasting young in these time-frames, as they have finished. The real compromise might be more regarding the total numerical production of bulk weight and/or extracts. Still though, 20%+ THC and half a Kg per sqm isn't a hard limit. I just can't see any reason for 10 week plants in my space. Though I'm not blind to the fact 7 weeks is enough, and in 10 weeks I can do something too good for a dispensary. What is 'enough' really depends on the consumer. People around me are open jawed when they hear how fast I'm moving through phases. Thinking they just couldn't do it. A type of disbelief, that says a lot.