How much light is too much.........?
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tusseltussel
Well-Known Member
so you just renforced what i said and that other sentance was directed at the op that said i was mean, and yes lighting makes sense to me but growing in a 2x2 area when you got enoough light to grow more plants of the same quality in a bigger room makes no sense. read the whole thread and you would know that. i dnt need you to do the math for me i already know these things and i know all you need is 5-7000psf and thats it no more no less. chk all the growing info out ther it will tell you 3,000 minimum but that will give you light airy buds, 5-7 nice big dense nuggets ,27.5 a waste of money, your losing money on the llight you bought the electric you pay and the weed your not growingboth of those sentences seem to mean entirely different things...
i did a little bit more research... seems like the accepted number for highest sunlight intensity is 10,000 lumens/sq ft... the highest i've heard of anyone recording is 13,011.
by my count each 400w light should be producing 55K lumens, totaling 110K.
he's running with 4 sq ft of floor space... so thats 27.5K lumens/sq ft...
27,500 lumens / 10,000 lumens = 275% brighter (best case)
27,500 lumens /13,000 lumens = 211% brighter (compared to highest value i found recorded)
either way - its really bright - the pics i'm sure dont do it justice, because your monitor cant blind you
make sense now?
BloodShot420
Well-Known Member
yeah - i SHOULD read the whole thread... i just jump in and do all this math, and i dont even know what thread i'm posting it in.... i'm just lucky it even makes sense in this conversation.
the 5000-7000 lumens/sq ft is not bright enough for me...
although, 5000-7000 will grow a plant, it wont grow the kind of plant i'm after...
and its definitely not a waste of money to add more light, as i said before, i can power my whole grow for 3 months for less than i would buy 1/2 oz on the streets... and in the end, i'll have LBs... not fractions of an oz.
oh shit - is this even the right thread??
the 5000-7000 lumens/sq ft is not bright enough for me...
although, 5000-7000 will grow a plant, it wont grow the kind of plant i'm after...
and its definitely not a waste of money to add more light, as i said before, i can power my whole grow for 3 months for less than i would buy 1/2 oz on the streets... and in the end, i'll have LBs... not fractions of an oz.
oh shit - is this even the right thread??
tusseltussel
Well-Known Member
if you know how to grow right all you need is 5-7000. indoors you dnt grow tall plants its a waste,even up your canopy and your good i can pull 10 oz off my 400w light in my 3x3 room evey 2 months by veging in a seprate room while flowering, if i add another month veg i could pull a lot more and the nugs are dense as can be and quite powerful..... why do you need a brighter room.... you can pull pounds off a 400 watter if you know what your doing
so what kind of plant are you looking for????? the end product is what i look for and i get high quality dense nuggs with 5000, its not about how much you pay for electric its how much your loosing be not useing the extra light. use the light and grow more dank nuggets, how do you argue that??? dank nuggets of high quality, thats the goal thats what 5-7000 will get you
Mr.J420
Well-Known Member
Meangreen, nice setup man, cant really weigh in on if its too much light from experience. Just use one light next grow and see if you get less then you will know for sure if you are wasting money on elec bills.
Those are sweet cool tubes, what did you use to make them? they look alot bigger than the standard bake a round tubes.
Those are sweet cool tubes, what did you use to make them? they look alot bigger than the standard bake a round tubes.
tusseltussel
Well-Known Member
A great deal of importance has happened in research investigating photosynthetic response to environmental stress in the 25 years since the last anniversary issue of Plant Physiology. However, from my perspective, the importance of one set of discoveries stands out from the others for its far reaching influence on how we think about the photosynthetic response to a wide range on environmentally imposed limitations. As little as 15 years ago it was generally held that the success of plants in their environment was dictated by strategies that maximized the rate of photosynthesis. Further, maximum photosynthetic capacity was thought to be largely a static characteristic of individual leaves that was established during development. This view has now given way to the recognition that the regulation of photosynthesis in response to the environment is highly dynamic and dominated by a photoprotective process, the non-photosynthetic thermal dissipation of absorbed light, which was entirely unknown at the time of Plant Physiology's 50th Anniversary. This brief overview describes what is currently understood about this centrally important photoprotective process and highlights areas of current inquiry that may presage a detailed mechanistic understanding in the near future
Most days plants encounter light intensities that exceed their photosynthetic capacity. Exactly what constitutes excess light for a leaf depends on its instantaneous environmental conditions and can vary over an exceedingly wide range of irradiance levels. For example, irrigated field-grown sunflower is typical of C3 crop plants, exhibiting maximum photosynthetic capacity during mid-morning with photosynthesis declining throughout the afternoon as stomatal conductance declines in response to declining leaf water potentials . Thus even under conditions which may not generally be considered stressful, stomatal conductance can substantially restrict CO2 entry into leaves, rendering even moderate irradiances in the top of a crop canopy in excess of photosynthetic capacity.
When environmental conditions prevent the maintenance of a high capacity for photosynthetic and photorespiratory carbon metabolism to utilize absorbed light, the likelihood for the photosynthetic generation of biologically damaging molecules including reduced and excited species of oxygen, peroxides, radicals, and triplet state excited pigments increases dramatically. Although some plants can reduce the amount of incident light that is absorbed through strategic leaf and chloroplast movements, rapid reduction in light absorption appears to play only a minor role in the challenge of coping with excess light.
The development of the techniques and biophysical interpretation of pulse modulated fluorescence in the mid-1980s by Bradbury and Baker (2) bolstered by important additions and refinements by many others provided the basis for a new understanding about the dynamic trade-off between photosynthetic efficiency and photoprotection. A wide range of studies on many different species revealed that frequently over one-half of the light absorbed by photosystem II (PSII) chlorophylls in healthy, fully functional leaves can be redirected by a process that operates within the antenna ensemble of PSII, which harmlessly discharges excess photon flux energy as heat . This thermal dissipation process is measured and often called non-photochemical quenching, referring to the fact that the thermal dissipation of chlorophyll excited states competes with fluorescence emission as well as with photochemistry (i.e. photosynthesis).
not sure what this means but i found it interesting, seems like plants can get too much light..... this is just general plant info and not spacific to marijana
In photosynthesis, an ultraefficient charge transfer reaction converts virtually all incoming light energy into electrochemical energy. But such efficiency can be dangerous to the plant when there's too much light. "If the light gets too bright, then the reaction center works too fast and produces a lot of high-energy intermediates that don't have anywhere to go because the system is jammed up down the line," says Devens Gust, one of the leaders of the Arizona State team.
Plants keep themselves from burning out through nonphotochemical quenching, that is, by dissipating excess absorbed energy as heat. Inspired by this process, Gust and his coworkers designed a molecule that converts absorbed light to electrochemical energy but reduces the efficiency of the conversion, its quantum yield, as the light intensity increases.
The molecule consists of two light-gathering antennas, a porphyrin electron donor, a fullerene electron acceptor, and a control unit that reversibly photoisomerizes between a dihydroindolizine (DHI) and a betaine (BT) (Nat. Nanotechnol., DOI: 10.1038/nnano.2008.97). The DHI form doesn't effect the electron transfer between the porphyrin and the fullerene. In contrast, the BT form is "able to suck the excitation energy out of the porphyrin antenna system," thereby inhibiting electron transfer, Gust says.
At low light levels, most of the molecules are in the DHI form, and the system has a quantum yield of 82%. At higher light intensities, more of the molecules convert to the BT form, reducing the electron-transfer quantum yield to as low as 27%. When the light intensity goes back down, the molecule reverts to the DHI form.
Most days plants encounter light intensities that exceed their photosynthetic capacity. Exactly what constitutes excess light for a leaf depends on its instantaneous environmental conditions and can vary over an exceedingly wide range of irradiance levels. For example, irrigated field-grown sunflower is typical of C3 crop plants, exhibiting maximum photosynthetic capacity during mid-morning with photosynthesis declining throughout the afternoon as stomatal conductance declines in response to declining leaf water potentials . Thus even under conditions which may not generally be considered stressful, stomatal conductance can substantially restrict CO2 entry into leaves, rendering even moderate irradiances in the top of a crop canopy in excess of photosynthetic capacity.
When environmental conditions prevent the maintenance of a high capacity for photosynthetic and photorespiratory carbon metabolism to utilize absorbed light, the likelihood for the photosynthetic generation of biologically damaging molecules including reduced and excited species of oxygen, peroxides, radicals, and triplet state excited pigments increases dramatically. Although some plants can reduce the amount of incident light that is absorbed through strategic leaf and chloroplast movements, rapid reduction in light absorption appears to play only a minor role in the challenge of coping with excess light.
The development of the techniques and biophysical interpretation of pulse modulated fluorescence in the mid-1980s by Bradbury and Baker (2) bolstered by important additions and refinements by many others provided the basis for a new understanding about the dynamic trade-off between photosynthetic efficiency and photoprotection. A wide range of studies on many different species revealed that frequently over one-half of the light absorbed by photosystem II (PSII) chlorophylls in healthy, fully functional leaves can be redirected by a process that operates within the antenna ensemble of PSII, which harmlessly discharges excess photon flux energy as heat . This thermal dissipation process is measured and often called non-photochemical quenching, referring to the fact that the thermal dissipation of chlorophyll excited states competes with fluorescence emission as well as with photochemistry (i.e. photosynthesis).
not sure what this means but i found it interesting, seems like plants can get too much light..... this is just general plant info and not spacific to marijana
In photosynthesis, an ultraefficient charge transfer reaction converts virtually all incoming light energy into electrochemical energy. But such efficiency can be dangerous to the plant when there's too much light. "If the light gets too bright, then the reaction center works too fast and produces a lot of high-energy intermediates that don't have anywhere to go because the system is jammed up down the line," says Devens Gust, one of the leaders of the Arizona State team.
Plants keep themselves from burning out through nonphotochemical quenching, that is, by dissipating excess absorbed energy as heat. Inspired by this process, Gust and his coworkers designed a molecule that converts absorbed light to electrochemical energy but reduces the efficiency of the conversion, its quantum yield, as the light intensity increases.
The molecule consists of two light-gathering antennas, a porphyrin electron donor, a fullerene electron acceptor, and a control unit that reversibly photoisomerizes between a dihydroindolizine (DHI) and a betaine (BT) (Nat. Nanotechnol., DOI: 10.1038/nnano.2008.97). The DHI form doesn't effect the electron transfer between the porphyrin and the fullerene. In contrast, the BT form is "able to suck the excitation energy out of the porphyrin antenna system," thereby inhibiting electron transfer, Gust says.
At low light levels, most of the molecules are in the DHI form, and the system has a quantum yield of 82%. At higher light intensities, more of the molecules convert to the BT form, reducing the electron-transfer quantum yield to as low as 27%. When the light intensity goes back down, the molecule reverts to the DHI form.
MEANGREEN69
Well-Known Member
No worries Bloodshot, it's nice to be able to debate something on here, without it becoming a trade of insults, just cos we don't agree. So thank you for your patience
Oh and one thing we both agree on, is it's definately not to much light. I have a 600w digital in a cooltube between 1-2 foot above mine and they love it! If I could keep a 1kw light cool enough, at the same distance from my plants, it would be there in an instant.
Meangrean, if you do have those plants 1 foot away from the bulb then I apologise, I saw one picture of your lights, right at the top of the cab, and assumed that was their permanent position. If they are 1 foot away, and the plants are not experiencing excessive heat, then you are indeed using them efficiently/to their maximum potential.
Thats me done anyway, I'll shut up now
Have a good Xmas both.
Peace.
it's all good bro....yeah i do move the lights i move the plants closer to the bulbs...its all good
MEANGREEN69
Well-Known Member
tusseltussel
Well-Known Member
its cool man if you dnt have more room but i did post info on how you can have too much light, its not marijuana spacific but it is photosynthisis spacific and yes you can have too much read the posts too much light will slow growth. good luck still seems like a waste when 400 watts is whay more than enough for a 2x2 room why not spend that money on co2 or somthing that will make a difrncemaybe some ppl dont have the roomso they use a 2x2x4 cabby
tusseltussel
Well-Known Member
i will poke around and find a link 4 ya, its hard to find though cause ther hasnt been much research on the subject, i havnt been able to find a number to put to it as a maximum but im sure brighter than anywhere on earth is prolly a lil exessive, i'll see what i can do
MEANGREEN69
Well-Known Member
tusseltussel
Well-Known Member
here is an interesting read. im not done reading it yet but figured i would post it
http://www.sci-journal.org/index.ph.../a1/index.htm&link=reports/home.php&c_check=1
http://www.sci-journal.org/index.ph.../a1/index.htm&link=reports/home.php&c_check=1
BloodShot420
Well-Known Member
that basically says, co2 doesnt help until the lights are of a certain intensity, then co2 helps a lot...
that much light definitely does not hurt the plants, mine are healthy and green down to the root... every leaf is as big as it would be if it were in the sun... if you look up through the canopy, its still pretty bright.
and i use 2KW in my small garden because i can yield the most off of that combo of lights... 2x 400w's would not get me lbs of fat colas in my closet... 2 600s could maybe come close, but i can manage the heat and the bills from the 1Ks and the plants love it... and when i get my co2 hooked up i expect them to grow much faster
that much light definitely does not hurt the plants, mine are healthy and green down to the root... every leaf is as big as it would be if it were in the sun... if you look up through the canopy, its still pretty bright.
and i use 2KW in my small garden because i can yield the most off of that combo of lights... 2x 400w's would not get me lbs of fat colas in my closet... 2 600s could maybe come close, but i can manage the heat and the bills from the 1Ks and the plants love it... and when i get my co2 hooked up i expect them to grow much faster
MEANGREEN69
Well-Known Member
HerbalPrincess
Member
Ok theres alot of wrong information here and I feel the need to clarify. Lumens is a measure of light energy. Intensity is a measure of Lumens per square foot. If you have a bulb that produces 55k lumens, that is how much the bulb produces. period. It doesn't produce any less lumens when you are farther from the bulb, because lumens aren't a unit of intensity. That would be like saying a fire doesn't produce as much heat when you are farther away from it. The fire doesn't care how close you are to it, it keeps burning at the same rate and producing heat at the same rate. It doesn't feel as hot when you are further away because you are absorbing a smaller percentage of the fire's heat, since at an increased distance the radiation from the fire is spread across more surface area.
The intensity, however, does diminish as you move further from the bulb. This is why the light is less bright further from the bulb, as perceived brightness is a qualitative measure of intensity. The inverse square law assumes that the light source is a point source, and is derived directly from spherical geometry noting that the surface area of a spherical shell centered on the light source increases as the square of the distance from the source.
If you want an equation, surface area = 4*pi*d^2 where d is the distance from the source. Intensity is Energy/Area, so for a constant initial lumen output, L, intensity = L/(4*pi*d^2)
This shows that for a point source, the intensity is inversely proportional to the square of the distance from the source, as in the inverse square law.
This is not valid when your light source can no longer be approximated as a point source; which unless you're using a very small bulb very far away from your plants in a room painted black, isn't a good approximation for your grow lights.
Also don't grow with a very small bulb very far away from your plants in a room painted black. thats stupid.
To find the average intensity, take the total lumens produced by your lights, and divide that by the surface area the light is spread upon. If you have a reflective tent, and your light is evenly distributed, the amount you calculate this way will be in agreement with what you find using a light meter. Keep in mind that the further you are from your light, the more surface area light is projected upon, and therefore the intensity will be lowered, though not at the rate described by the inverse square law.
Actually lux is lumens per square meter. So if what you said is true 1 ft is about .3 meters, so 1 sqft is about .1 sq meter. so 55k/.1 would put your intensity at over half a million lux, four times that of the brightest sunlight on the surface of the earth. Try to burn some ants with a magnifying glass in your grow room and you will see this is not true.
so wrong. If you put two lights in the same space, you just doubled your lumen production. If your lighted area is constant, you just doubled your intensity. If you want to do an experiment go to a dark room and light a candle. now light ten candles. does it look brighter?
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