sorry typo 2000
New LED lights stretching
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grotbags
Well-Known Member
just your typo...
The best way to know if their numbers are solid or not is to see if they testing in a integrating sphere. It's the best way most appropriate way to isolate the light form the unit and drive to an accurate result. Gavita uses integrating spheres for testing. A company like Spider Farmer openly admits to testing in tents. In tents you can get additional boost from refractory properties of the walls and light pollution. Another way is to look at their advertised numbers and their DLC results if they are certified. I've noticed a few companies advertised results can be different from their DLC stated specifications.
Do you have a citation for those testing studies done in Israel?
There have been some decent studies in recent years that are supporting the use of different spectra.
Magagnini shows a comparison between HPS and LED https://www.karger.com/Article/Fulltext/489030#ref22
The Jenkins has data on UV https://www.scirp.org/journal/paperinformation.aspx?paperid=113836
(PDF) Influence of Light Spectra on the Production of Cannabinoids
PDF | In recent years, more attention has been paid to cannabis from both medical and political points of view. This study investigates the influence of... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
The Amrein really breaks down spectra and show direct correlation to yield
(PDF) Influence of Light Spectra on the Production of Cannabinoids
PDF | In recent years, more attention has been paid to cannabis from both medical and political points of view. This study investigates the influence of... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
While this is great research its just the tip of the iceburg, there needs to be more research conducted. Forums like this are appreciated but different geno and chemotypes of plants can also produce difference results. We're still in the wild wild west of fully understanding spectral cultivation.
LOLjust your typo...
grotbags
Well-Known Member
your right there cowboy!!! were in the wild west alright and ive got myself an ithcy trigger finger!...
jimihendrix1
Well-Known Member
The study done in Israel was on PBS TV more than 20-25 years ago. Early 90s.The best way to know if their numbers are solid or not is to see if they testing in a integrating sphere. It's the best way most appropriate way to isolate the light form the unit and drive to an accurate result. Gavita uses integrating spheres for testing. A company like Spider Farmer openly admits to testing in tents. In tents you can get additional boost from refractory properties of the walls and light pollution. Another way is to look at their advertised numbers and their DLC results if they are certified. I've noticed a few companies advertised results can be different from their DLC stated specifications.
Do you have a citation for those testing studies done in Israel?
There have been some decent studies in recent years that are supporting the use of different spectra.
Magagnini shows a comparison between HPS and LED https://www.karger.com/Article/Fulltext/489030#ref22
The Jenkins has data on UV https://www.scirp.org/journal/paperinformation.aspx?paperid=113836
(PDF) Influence of Light Spectra on the Production of Cannabinoids
PDF | In recent years, more attention has been paid to cannabis from both medical and political points of view. This study investigates the influence of... | Find, read and cite all the research you need on ResearchGate
The Amrein really breaks down spectra and show direct correlation to yield
(PDF) Influence of Light Spectra on the Production of Cannabinoids
PDF | In recent years, more attention has been paid to cannabis from both medical and political points of view. This study investigates the influence of... | Find, read and cite all the research you need on ResearchGate
While this is great research its just the tip of the iceburg, there needs to be more research conducted. Forums like this are appreciated but different geno and chemotypes of plants can also produce difference results. We're still in the wild wild west of fully understanding spectral cultivation.
ChongMaBong
Well-Known Member
Hi jimi I have been looking at that gavita would you say that its a decent light?
Gavita Pro 1700e LED Grow Light 645w
Please note these are purchase to order and land with us within 1-2 working days Runs at 2.6 µmol per watt - get more light for the same power useage! By comparison, the very best professional HPS grow lights produce only 2.1 µmols per watt and most produce a lot less (down to as little as 1.8...
www.onestopgrowshop.co.uk
grotbags
Well-Known Member
it was 2 years ago...Hi jimi I have been looking at that gavita would you say that its a decent light?
Gavita Pro 1700e LED Grow Light 645w
Please note these are purchase to order and land with us within 1-2 working days Runs at 2.6 µmol per watt - get more light for the same power useage! By comparison, the very best professional HPS grow lights produce only 2.1 µmols per watt and most produce a lot less (down to as little as 1.8...
ChongMaBong
Well-Known Member
What was 2 years ago?
Kassiopeija
Well-Known Member
I could care less about the lights used. I was only showing examples of what research papers are out there. We need more research with more lights and strains
Kassiopeija
Well-Known Member
it's not about the lights per se but the work is full of methodological errors
which casts a huge shadow of doubt on the legitimacy of the results
they are claiming to flower out cannabis at "optimal conditions" but target 500 umol ppfd for flower
they veg under 400W MH 18/6 but flower under 275W HPS at 12/12 [!!!] even dimming
measuring ppfd at different heights (the LEDs in greater distance to arrive at the same numbers lol!)
alot of data is missing, esp. for the LED, not even the plants are shown, for the flower tent they duplicate all the veg pics
basically light-starving all plants, no wonder an almost monochromatic mostly 660nm spec fared best...
You can tell these are academics doing this work and not growers, that or they have an agenda but atleast the work is transparent so you can poke those holes in it. What we need moving forward is growers and industry experts working on these papers with academia.
grotbags
Well-Known Member
the light was a good light two years ago... not so much today.
jimihendrix1
Well-Known Member
The Gavita is a great light, and compares to any light with the same wattage made today. The 1700e has 3300 diodes. 1781umol. Also has a 5 Year warranty.
Gavita also makes the 1930e, which is 1930umol, and is supposed to replace a DE HPS. Its 780w. It will cover a 5 x 5 area.
Gavita also makes the 1930e, which is 1930umol, and is supposed to replace a DE HPS. Its 780w. It will cover a 5 x 5 area.
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Kassiopeija
Well-Known Member
believe me I have sighted hundreds after hundreds of legit studies but this isnt one. not really transparent and full of flaws. their conclusion is that the "plurple spec" is best...
grotbags
Well-Known Member
im not saying its bad just for that price today you can get cheaper and more efficient...
grotbags
Well-Known Member
@Kassiopeija i seen these posted on another forum and thought you might find them interesting,
https://www.quantamagazine.org/why-are-plants-green-to-reduce-the-noise-in-photosynthesis-20200730/
http://www.esalq.usp.br/lepse/imgs/conteudo_thumb/Why-did-chlorophyl-evolve-to-be-green-as-opposed-to-black.pdf
https://www.quantamagazine.org/why-are-plants-green-to-reduce-the-noise-in-photosynthesis-20200730/
http://www.esalq.usp.br/lepse/imgs/conteudo_thumb/Why-did-chlorophyl-evolve-to-be-green-as-opposed-to-black.pdf
Kassiopeija
Well-Known Member
I'm sorry the first is really esoteric, and both theories or write-ups still make the old error in thinking that chlorophylls can't absorb green photons. they can - and do.
they are mislead by measurements of broken chl mols on diethyl-ether or acetone, which doesnt give a realistic information on how light is being absorbed when said chlorophyll is a part of the light-harvesting complexes.
From the comments:
(he has it down)
"Aquila2 years ago
Is this article actually serious? The energetics of the electron transfer chain are v v well known including photon energy level requirements and antenna pigment based non photochemical quenching, carotenoid protection and xanthophyll cycling. The energetic levels of photons passing thru PS1 & 2 have to be appropriate to keep the system balanced and operating smoothly. Fine tuning is done v rapidly within the antenna by viola, anthera and zeaxanthin in higher plants and diato,diadinoxanthin in some algal species etc. Longer term protection involves other carotenoids but as they cant change form like the xanthophylls this is basically a protective covering thats v slow to react to changes in light and is more a long term adaptation to environment. If a plant let through all photons of all energetic levels it would literally fry the reaction centre D1 proteins like an egg and cease photosynthesis v quickly. I really dont understand why everything in this article they say is not understood has in fact been taught as pre degree biology for decades. Apart from needing to keep energetic flow through reaction centres in the light reactions stable.....a stable input to the Calvin cycle is also required and whacking in more energy after the dark reactions are saturated (pmax) is literally going to destroy the chloroplasts. Plants actually use WAY less than full sunlight photon doses (2000µmol photons per second per m2 for most lab experiments) regardless of what wavelength photons you provide, the light part of the PE curve becomes saturated at fairly low photon densities and trying to get that up any further is useless as it fries the reaction centres needlessly when the dark reactions are already at full pelt and is a massive cost to the cell to replace all the damage. The system HAS to be stable to operate but apart from that, trying to speed it up further would just result in total damage to reaction centres and the D1 & D2 proteins fusing to completely block RC2. All A level to basic biology degree level stuff thats been taught for literally decades. Far from 'unstatisfyingly wasteful' the system is beautifully designed to optimise photosynthesis under a wide range of conditions without frying every protein. I really am confused that the very basics of photosynthesis are described here as being unknown. Reactions to flicker effect btw are going to be governed by xanthophyll cycling which is a v v rapid way of altering non photochemical quenching.......already widely known and used in remote sensing (due to the reflectance change it causes around 531nm) as a way to detect photosynetic rates in plants. Exactly what photons and how many are used has been extensively studied using PAM fluorescence, again for many decades. Not that Gabor is particularly wrong about anything they say.. but opening a biology textbook would have answered every question in seconds compared to however long this amazing research into things already well known took."
This review explains alot about the mystery & positive function of the green light, and why "only" 85% of it is absorbed.
(PDF) Importance of the green color, absorption gradient, and spectral absorption of chloroplasts for the radiative energy balance of leaves
PDF | Terrestrial green plants absorb photosynthetically active radiation (PAR; 400–700 nm) but do not absorb photons evenly across the PAR waveband.... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
jimihendrix1
Well-Known Member
Not really
The HLG 650R is 630w, has the same umol as the Gavita. The HLG 650r has 2592 Diodes, and the Gavita has 3336 Diodes.
So that right there gives 744 more Diodes with the Gavita. Easing the load and heat production per diode. Extending the life of the diode.
The Gavita spreads the light out better
You can get the Gavita for $1002 at Hydrobuilder
The HLG 650R costs $1100 at Hydrobuilder
The Gavita runs cooler
- While the HLG may be, but Ive not seen it advertised as CE and CB compliant, and the Gavita has a wider ambient air operating temperature.
Wet Rating
IP66 wet rated and UL8800 compliant for use in wet environments which allows versatile placement in growing spaces.
Its IP66 wet rating provides complete protection from dust, oil, and water, allowing you to mount this light source in low rooms, on vertical racks, over rolling benches
The Gavita has Phillips Driver
HLG has a Meanwell. Not saying mean well arent good. But Ill take the Phillips any day. Phillips has been in business making electronic equipment for 131 years. Since 1891
Mean Well has been in business since 1982
Mean Well Drivers are made in China
Phillips Drivers are made in Netherlands
As of 2012, Philips was the largest manufacturer of lighting in the world
The HLG has a 3 year warranty.
The Gavita has a 5 years warranty.
Ill take the Gavita anyday, everyday.
The only drawback with the Gavita is that you have to spend another $$78 at Growers House for the dimming module. Some places want as much as $130. Gavita still comes in cheaper than the HLG 650R. HLG $1100 vs $1080
I dont see 1 advantage with the HLG vs the Gavita. Especially since the Gavita has 744 more diodes, and 2 more years on the warranty. 5 years vs 3 years. Gavita has a 40% longer warranty