CMH vs LED vs HPS

[jwm]

I have harvested my first run under LEDs after many years with HPS, I had trouble to keep the temperatures high enough for the plants to give all their potential. I made 380g with a Lumatek Zeus of 465w, it was used first at 25% then to 100%, on this run the yield is the same I had with 600w HPS so it's more effective even if it's possible to do better with the LED I have. The quality however is really nice, the smell and taste are very powerful and the high is very satisfying and long lasting.
I think the plants are more leafy under LED but as they are full of resin it's perfect to make some Haschich. The trim was fresh frozen to avoid to get pieces of dry leaves with the trichomes, this run of ice o made a fantastic result, I got 7g but I don't know how much plant material was used. I think around 70/80g of dry material.
After one run I can't yet judge if the LED are really better than the HPS but so far I'm happy to have switch and the next months who will get warmer it will really helpful to have a light source who don't produce heat.

I’ll be surprised if you went back…

 

[jwm]

Is anyone successful in using led with low humidity and lower temps? I am switching to cmh after 4-5 years of using led. The micro management of environment with led was getting to me.
Especially in veg with led I stunted to many plants when environment and light levels were incorrect. Been using cmh/hid to veg lately because of this. Also I hate ultrasonic humidifiers with a passion is there a better alternative?

I started 15-20 yrs ago w/ CMH. Loved them. Took yrs off, now in a small 3x2 and using LED and love the low heat and incredible growth.

 

[Ca++]

Raman scattering occurs at extremely low levels, only about 1 out of 10 million photons experiences Raman shift when interacting with a molecule. The vast majority goes through elastic scattering, aka no frequency shift.

It looks pretty effective in the pics.
I'm trying different different angles, to try and show the same thing thing. That all the electric used at the lamp isn't making heat or IR that makes heat. That light doesn't come for free. Then that later, like IR, light heats what it hits. It just takes a few more tries. We have something like a 10% light to heat conversion, even with the most reflective of surfaces. The explaination in the link offers good insight. Even practical uses.

I imagine that most light particles that interact, are not loosing under 50% and so vanish from view. For example, red loosing just 10% of it's energy, makes it vanish into IR, that probably gets fully entangled.

1 in 10,000,000 sounds low. Do you have anything? Light hitting a surface with such little interaction seems implausible.

 

[Dr.Mantis]

It looks pretty effective in the pics.
I'm trying different different angles, to try and show the same thing thing. That all the electric used at the lamp isn't making heat or IR that makes heat. That light doesn't come for free. Then that later, like IR, light heats what it hits. It just takes a few more tries. We have something like a 10% light to heat conversion, even with the most reflective of surfaces. The explaination in the link offers good insight. Even practical uses.

I imagine that most light particles that interact, are not loosing under 50% and so vanish from view. For example, red loosing just 10% of it's energy, makes it vanish into IR, that probably gets fully entangled.

1 in 10,000,000 sounds low. Do you have anything? Light hitting a surface with such little interaction seems implausible.

I can certainly give you some references for Raman if you want to dig in a little bit more, it’s something I researched in school for many years. The reason why it’s so low comes down to probability in the quantum state. Basically, I’m Raman, you excite a bond to a “virtual state”, and decay to n = n+ or - some integer (depending on temp). With regular scattering you land back on the ground state, which is much more probable, and the photon leaves with the same energy it went in with.

In plants the chlorophyll absorbs photosynthetically active light to become an excited singlet state. That excited chlorophyll can basically go three different ways. Electron transfer to the photo systems. Intersystem crossing to the triplet state, followed by quenching - this is how plants turn light into heat. And finally, fluorescence, where the chlorophyll is excited to a real state and re emitted at a different wavelength along with loss of energy, again in the form of heat.

I don’t know, but my suspicion is most of the heat from non biological sources is the result of absorbance by chromophores and vibrational decay.

 

[Cactus Squatter]

But it takes a REAL masochist to try to get a good crop with LED's. LOL!

Not really. I adapted after 1 grow.

I love CMH setup but it doesn’t hold up to my Gavita 1700e.

 

[Jellyfish]

Not really. I adapted after 1 grow.

I love CMH setup but it doesn’t hold up to my Gavita 1700e.

Good for you, sincerely. LED's did not work out for me.

 

[Vegg69guerilla]

4 days under a dialled 400w sunmaster in a m3 area with controlled and managed heat exchange shows you exactly that the closest you will get to radiant sunshine in compact form indoors will always be high pressure sodium..the light is so intense compared to leds its frightening and once dialled there is no better light source..but that is my humble opinion over 5 decades of dirt..science has it wrong to a degree here and its just opinion..


and in hindsight I regret walking into this thread and undermining a whole light science...it obviously gets you reaction which I maybe wanted but I can see there is an army of well established led growers everywhere..I wasn't questioning personal grow styles or skills..I was just documenting what hps lighting does when applied correctly in version to modern day technology..so confident I am in this belief that if show it in pics and not in words it seems to effect differently..the leafset has a complete different biological response to the radiant par emitted and i still believe is the only lighting left possibly in the world that releases the hard to find cannabinoids and highs we seem to be losing ever so frequently..I just don't think the chemical exchange that happens when led light touches leafsets exposes enough of what hps unravels...pure radiant light intensity that closely mimics the sun this way seems to excite a plant like no other lighting..I cannot walk in my tent room without dark glasses on and that in my eyes denotes exactly what the sun does when I look in the sky..I can't.. and once you have this replica of that sunshine it is unbeatable in terms of plant health vitality and vigour..it feeds the leaf like I've seen no other..sorry if I waltzed in chatting shit and denouncing ppl with led lighting..I'm mad at the system not you..

 

[smirnoff420]

BTW many homegrowers are actually using PC vents to push the little LED heat down to the plant canopy as a means to get leaf surface temps into a more optimal range. Some genetics just feel better with warmer temps than the standard 25°C for C3 plants.

Unfortunately many people are doing it wrong, it's quite counter-intuitive. Best is to point fans at the LEDs from the bottom to get the heat from them down to the plants. Also there is less IR heat, so one needs higher air temperature to get the same leaf temp. I found that 28-30C is good with LEDs, below that, plants grow slower.

 

[greyfader]

4 days under a dialled 400w sunmaster in a m3 area with controlled and managed heat exchange shows you exactly that the closest you will get to radiant sunshine in compact form indoors will always be high pressure sodium..the light is so intense compared to leds its frightening and once dialled there is no better light source..but that is my humble opinion over 5 decades of dirt..science has it wrong to a degree here and its just opinion..


and in hindsight I regret walking into this thread and undermining a whole light science...it obviously gets you reaction which I maybe wanted but I can see there is an army of well established led growers everywhere..I wasn't questioning personal grow styles or skills..I was just documenting what hps lighting does when applied correctly in version to modern day technology..so confident I am in this belief that if show it in pics and not in words it seems to effect differently..the leafset has a complete different biological response to the radiant par emitted and i still believe is the only lighting left possibly in the world that releases the hard to find cannabinoids and highs we seem to be losing ever so frequently..I just don't think the chemical exchange that happens when led light touches leafsets exposes enough of what hps unravels...pure radiant light intensity that closely mimics the sun this way seems to excite a plant like no other lighting..I cannot walk in my tent room without dark glasses on and that in my eyes denotes exactly what the sun does when I look in the sky..I can't.. and once you have this replica of that sunshine it is unbeatable in terms of plant health vitality and vigour..it feeds the leaf like I've seen no other..sorry if I waltzed in chatting shit and denouncing ppl with led lighting..I'm mad at the system not you..

your problem with your reply is that it is so highly subjective with zero science behind it.

you show 10 pics of one plant as if it conclusively proves your point.

you are so incredibly wrong. and i'm not mad or picking on you. i think you are sincere and mean what you say.

but that still does not make a grossly wrong statement right.

a hps fixture is most definitely not:

"the closest you will get to radiant sunshine in compact form indoors will always be high pressure sodium..the light is so intense compared to leds."

they are not more intense than a led array of the same power. in fact, they are less intense in the par range given equal power because so much of the hps is in the infrared range. you are reporting your personal impressions based on your human vision.

the plant does not see light the same way you do. here is a basic comparison of varioius light sources, including hps.

this shows that your statement is wrong. this shows that the hps has the least sunlike spectrum except for the blurple.

you have also refused to comment on my post #823, which was directed specifically at you.

i hate to bore everyone else to tears but i will once again include a pic of one of my led grows. this one used 6500k color temp leds.

the row is 60 ft long and 5 ft wide. each 5x5 has 720 watts of 6500k cree diodes above it. there are 10 rows.

the strain is purple mesa cbd and it lab tested at 18% and stunk up the street outside the building so bad the cops came because they had received anonymous tips that we were growing weed there.

i was the director of this facility. i also designed and supervised the build and taught everyone how to use it.

as this was a legal facility we were required by the state to use their approved lab to verify that thc was below .03%. so we had a state verified cbd content of 18%, which is huge for a cbd plant.

have you personally ever used a led array? do you have a par meter? i do and it tells me that leds are

more "intense" in the par range than a hps of similar power.

 

[Corpselover Fat]

. est is to point fans at the LEDs from the bottom to get the heat from them down to the plants.

You can also suck air out from down low. Should help some.

 

[Hammerhead]

For CMH Pick a bulb that is as close to the sun spectrum as you can find. I use GC 3k/4k bulbs mixed together in flower,, In veg all 4k bulbs.

 

[Ca++]

That 360w/m3 6500K looks better than expected. I don't know the strain, but in respect of the leaf quantity, have you seen it under warmer lighting?

 

[Ca++]

You can also suck air out from down low. Should help some.

A Doughnut shaped light, with reversible fan in the middle, could be useful. Our weather here goes from too hot to too cold seasonally, the ability to extract or recycle would be nice.

 

[greyfader]

That 360w/m3 6500K looks better than expected. I don't know the strain, but in respect of the leaf quantity, have you seen it under warmer lighting?

well, the plants in the pic were just stripped of most fans as we harvested them soon after. probably the next day.

but no, we didn't use any other spectrum.

 

[Crooked8]

your problem with your reply is that it is so highly subjective with zero science behind it.

you show 10 pics of one plant as if it conclusively proves your point.

you are so incredibly wrong. and i'm not mad or picking on you. i think you are sincere and mean what you say.

but that still does not make a grossly wrong statement right.

a hps fixture is most definitely not:

"the closest you will get to radiant sunshine in compact form indoors will always be high pressure sodium..the light is so intense compared to leds."

they are not more intense than a led array of the same power. in fact, they are less intense in the par range given equal power because so much of the hps is in the infrared range. you are reporting your personal impressions based on your human vision.

the plant does not see light the same way you do. here is a basic comparison of varioius light sources, including hps.

this shows that your statement is wrong. this shows that the hps has the least sunlike spectrum except for the blurple.

you have also refused to comment on my post #823, which was directed specifically at you.

i hate to bore everyone else to tears but i will once again include a pic of one of my led grows. this one used 6500k color temp leds.

the row is 60 ft long and 5 ft wide. each 5x5 has 720 watts of 6500k cree diodes above it. there are 10 rows.

the strain is purple mesa cbd and it lab tested at 18% and stunk up the street outside the building so bad the cops came because they had received anonymous tips that we were growing weed there.

i was the director of this facility. i also designed and supervised the build and taught everyone how to use it.

as this was a legal facility we were required by the state to use their approved lab to verify that thc was below .03%. so we had a state verified cbd content of 18%, which is huge for a cbd plant.

have you personally ever used a led array? do you have a par meter? i do and it tells me that leds are

more "intense" in the par range than a hps of similar power.

Ime he does not appreciate talk of any science. He is a “science doesnt know” guy. He was not only insulted when I tried to explain but resorted to name calling. Its likely not worth your time or effort.

 

[Vegg69guerilla]

your problem with your reply is that it is so highly subjective with zero science behind it.

you show 10 pics of one plant as if it conclusively proves your point.

you are so incredibly wrong. and i'm not mad or picking on you. i think you are sincere and mean what you say.

but that still does not make a grossly wrong statement right.

a hps fixture is most definitely not:

"the closest you will get to radiant sunshine in compact form indoors will always be high pressure sodium..the light is so intense compared to leds."

they are not more intense than a led array of the same power. in fact, they are less intense in the par range given equal power because so much of the hps is in the infrared range. you are reporting your personal impressions based on your human vision.

the plant does not see light the same way you do. here is a basic comparison of varioius light sources, including hps.

this shows that your statement is wrong. this shows that the hps has the least sunlike spectrum except for the blurple.

you have also refused to comment on my post #823, which was directed specifically at you.

i hate to bore everyone else to tears but i will once again include a pic of one of my led grows. this one used 6500k color temp leds.

the row is 60 ft long and 5 ft wide. each 5x5 has 720 watts of 6500k cree diodes above it. there are 10 rows.

the strain is purple mesa cbd and it lab tested at 18% and stunk up the street outside the building so bad the cops came because they had received anonymous tips that we were growing weed there.

i was the director of this facility. i also designed and supervised the build and taught everyone how to use it.

as this was a legal facility we were required by the state to use their approved lab to verify that thc was below .03%. so we had a state verified cbd content of 18%, which is huge for a cbd plant.

have you personally ever used a led array? do you have a par meter? i do and it tells me that leds are

more "intense" in the par range than a hps of similar power.

see there you go with attacking the truth again..don't shoot the messenger brother...you led boys will just not have it or understand because your fixed behind the best science in your mind..and you can sit here running off numbers and graphs and it doesn't mean anything. only to you in my eyes.

and I'm highlighting one plant here again to show you yet again..lolol.


I use 600w cool blue envirolights when I vegg which is close in reasoning to these leds in how the light will feed the leafset..I do it for 10 or 11 weeks in vegg with all females and normally under this scheme of light growth reported with my light cycle of 20/4 as 1.5-2" internodal spacing in vegg growth which is reasonable in most cases to report as fact.


I flip flowers from this reasonably pale 600w envirolight home they've had for 2.5 months to a 12/12 hps 400w sunmaster at 56000 lumens and perfectly matched in light intensity to that area, and virtually everytime I reverse the node spacing in half because the radiant light intensity limits stretch..reverses it in this case and the pic shown is an agent orange cross with haze heritage and I've cut in half its node spacing after extending dark periods from 4 hours in veg to 12 in flower..no led on earth I've seen reverses node growth..led hasn't that same intensity to limit stretch..its a science that can narrow close to hps harvests and I'm not questioning that but you are not releasing them same cannabinoids which I believe are incidental and the reason these once forgotten terp profiles are being lost..in layman's terms,led are not sweating this feature from the plant and for the love of you guys fighting me for it,I wish it did..lol

 

[Vegg69guerilla]

and another thing with indoor gardeners in general is they get there light scheme invariably completely wrong running 18/6 which seems to be the norm everywhere,that light cycle mimics the back end of summer in the wild,why would you growth and hormone a plant traditionally growing and building growth through early form in a light schedule that mimics flower in late summer?,makes no sense..20/4 is the only light schedule for led if I was using it..you bring the seed form from birth into mid summer on that light schedule and you mimic exactly the wild enviroment conclusive to its heritage...vegging all growth this ways mimics nature,18/6 mimics end summer lights..try version nature as close as possible and watch what happens to your vegg growth..!!!!

 

[Dr.Mantis]

see there you go with attacking the truth again..don't shoot the messenger brother...you led boys will just not have it or understand because your fixed behind the best science in your mind..and you can sit here running off numbers and graphs and it doesn't mean anything. only to you in my eyes.

and I'm highlighting one plant here again to show you yet again..lolol.


I use 600w cool blue envirolights when I vegg which is close in reasoning to these leds in how the light will feed the leafset..I do it for 10 or 11 weeks in vegg with all females and normally under this scheme of light growth reported with my light cycle of 20/4 as 1.5-2" internodal spacing in vegg growth which is reasonable in most cases to report as fact.


I flip flowers from this reasonably pale 600w envirolight home they've had for 2.5 months to a 12/12 hps 400w sunmaster at 56000 lumens and perfectly matched in light intensity to that area, and virtually everytime I reverse the node spacing in half because the radiant light intensity limits stretch..reverses it in this case and the pic shown is an agent orange cross with haze heritage and I've cut in half its node spacing after extending dark periods from 4 hours in veg to 12 in flower..no led on earth I've seen reverses node growth..led hasn't that same intensity to limit stretch..its a science that can narrow close to hps harvests and I'm not questioning that but you are not releasing them same cannabinoids which I believe are incidental and the reason these once forgotten terp profiles are being lost..in layman's terms,led are not sweating this feature from the plant and for the love of you guys fighting me for it,I wish it did..lol

I respect where you are coming from, and that is a nice looking plant imo. Just to set the record straight, science wasn’t always something journalists liked to talk about as a lofty idea reserved for the elite. Science is just testing hypotheses or ideas with empirical/hands on data to see how it holds up. Putting numbers to measurable parameters really enables information sharing in terms that can be somewhat objectively measured. So, while I agree no artificial light truly emulates the sun, and likewise, hid is very different from Led, how can we understand these things if we don’t try to measure what we can? Sure, our measurements may be lacking, or not truly representative, but we need to start somewhere. In essence, we need to capture and qualify the nuances of each light source, and the way the environment plays into it.

Personally, I’ve liked LED. Now that I’m flowering for the first time with Cmh, I really like it too. Although they are different from each other, what are the differences that are important? Is it the radiative heat of the Cmh? Is it the high ppfd of the led? Idk, I’ll shut up now.

 

[Vegg69guerilla]

it's the light spectrum with hps..and you know what?...I've sat for years now on multiple websites watching guys taking plants to near 90 days in flower and showing hps buds at day 50...and I'm not knocking the guys obviously dialling down expensive led grows..its them little guys with little dreams in little tents getting sucked into it and it actually breaks my insides watching it..this is nothing to do with knocking led but just steering ppl over to maybe more expensive alternatives but these alternatives are the only responsible way forward if we are really here furthering any advancement on what we're doing..and I only highlighted that node reversal and tightening when i take a plant from 4 hours darkness in vegg, to multiple 12 hour dark periods in flower because the light intensity and radiance seems to in many cases here, completely reverse node stretch in flower?...show me an led on earth that actually does this?..its a scary lightsource the old hps and once heat contained, limits many flowers from ultimate stretch..I've been In dirt 5 decades and I'd never come here to defame a led nation..but there's flaws that are instrumental in not achieving the same highs..leds are I believe just vanishing old terps..and I know you bring a version of something different growing under led but it's just not producing something missing that high pressure lighting seems to deliver..and if you make enemies of ppl who grow led how pathetic and shallow can that be really..I'm trading science is losing everything and led will trade,look at my yield and I can do the same thing.....erm no you can't.. it won't ever happen and the sooner the led stops leaving poor tent guys growing near 90 day buds just to get a yield then the world would be a better place..just awful viewing it and watching the truth...sorry if comments offend ppl but somewhere in some of your hearts you'll stop and think about it..and if you do and think positive then we might collectively all go back to finding it a lot easier to find the killer highs of yesteryear..led is like crack nowadays when you come online though...everyone's chasing the wrong sunset and it's upsetting,especially these little guys..!!

 

[Brother Nature]

^^^

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