2018 light efficiency ultimate battle

In your opinion what is the most efficient light source when comparing gram per watt of dried weight

  • LED (specify which one on the thread, diy, etc)

    Votes: 2 14.3%

  • HPS (specify which one on the thread)

    Votes: 3 21.4%

  • CMH / LEC (specify which one on the thread)

    Votes: 0 0.0%

  • Metal Halide

    Votes: 0 0.0%

  • CFL

    Votes: 1 7.1%

  • QBs or Cobs

    Votes: 8 57.1%
  • Total voters
    14
aerorev

aerorev

420 Member
First post in the forum. I’ve been growing for about 16 years mainly outdoor.

Started indoor a couple years ago using 1000w’s HPS’s with magnetic ballasts. Later on I switched to 400w Phillips HPS with Lumatek electronic ballasts for efficiency.

I’m seeing a lot of discussion and contradictory information on the efficiency of LEDs vs HPS vs CMH and I’m trying to clear the waters. If I’m making the full switch and investing a couple thousand I might be sure of what’s working better. I’ve seen side by side grows on forums and either some are poorly done without any kind of scientific method approach or they are biased. The cannabis industry is looking more and more like the fitness supplement industry with a lot of big brands marketing things with incorrect data.

In your opinion what is the most efficient light source when comparing gram per watt of dried weight? (Power consumption vs grams of dried weight)

Other factors and advantages such as heat emission, potency, cost of the equipment, etc are not to be compared. If some lights have better spectrum, etc is also not important. We will focus on gram per watt exclusively on this discussion and keep it focused around this subject.

Let me know about your personal opinion, links to properly done side by sides, etc…
 
Chris Scorpio said:
Other

QBs or Cobs
The new V2 Samsung diods are the shizzz
Click to expand...

QB's or cobs are a type of LED right? Any more info / grow using this lights? Have you got any link to a store selling them to check prices / specs? (I know I can google it but I want your opinion since you are vouching for them)

edit: added QBs or Cobs to the poll
 
To answer your titles question.. the Sun, nothing else comes close... build a greenhouse..
 
GrizzWald said:
To answer your titles question.. the Sun, nothing else comes close... biuld a greenhouse..
Click to expand...
Touche!!!!!

And we have a winner!!!
 
GrizzWald said:
To answer your titles question.. the Sun, nothing else comes close... build a greenhouse..
Click to expand...

I have grown outdoor most of my life but due to the circumstances I cannot atm. How I miss it! The terpene profile can't ever come close using artificial lights for now.
 
Sorry to be the buzzkill, but grams per watt comparisons only makes sense with clones grown in the exact same way with only different light sources, and to get acceptable statistical data it has to be repeated many times.
Opinion and subjective experiences hold little weight in scientific questions :Namaste:

GPW really doesn't mean anything since we're not including strain/pheno, gardening skills, veg time, growing method and turn around time in the equation, nor does ot say anything about % of cannabinoids obtained, which is one of the things more light gives you more of than increased dry weight of the herb.

I'll try to paint a few ''pictures'' explaining it.

A landrace sativa vs. a highly stable hybrid like Northern Lights in exactly the same setup will grow differently and yield very different resullts.

A SoG grow vs. one single big plant could get you the same GPW, but the SoG grow would do it 2-3 times faster than the big plant.


If you like keeping stats on yield, the two key performance indicators are g/m2 per day and total price per g (including all electricity used, nutes, medium, seeds/cost of keeping clones and mothers etc.)
-----------------------------------------------------------


The answer can be short and sweet, and have high probability of being true at the time of this being posted = Samsung LM301b middle power diodes.

NB! If you just want a bang for your buck and good lighting for full cycle growing and don't care about light science, just get +600 diodes (+900 for full saturation) in 3000K per m2 (10,8 sq. ft.) running at 60-80%, and stop reading now :D


Or the answer can be windy, abstract and vague at best, but without any statistical margin of error :)

In reality, measuring the actual photosynthetic efficiency of a light is a very complex task, and is not possible to do with the knowledge and technology currently available.

To break it down, plants respond in a variety of ways to different wavelengths, and timing and the lenght of exposure of said wavelengths.
There's both a photosynthetical value and a signalling value, ie. Far Red (730nm) creates almost no photosynthesis but accelerates photosynthesis of other wavelenghts and can be used to signal the plant to go into respiratory mode by havaing a few far red diodes on for one hour before lights out to 15 minutes after lights out, this will makes the plants ''think'' the night is longer and make it accelerate its fruiting process.

How to combine wavelengths, intensity and timing perfectly to a single phenotype alone is a study of several life times.



We can easily compare electrical efficiency of light sources of the same type and CCT using lumen per watt.
It doesn't say anything about the photosynthetical efficiency, but it's a fine guideline for output of light.


The best practical way is to use a proper quantum sensor (400nm to 700nm) and measure the PPFD at several points (center, sides and corner of every sq. foot) on given area, with the light from different distances from the surface each time.

However, PPFD does not take the photosynthetic value of the lightwaves in this range or the signalling value of any of the lightwaves into consideration.
Blue lightwaves in the 440-480nm range are a lot less photosynthetically efficient than red light waves in the 640-680nm range, but blue has effect on lateral branching, stretch, resin production and a much more.
Green lightwaves are less efficient than red and blue, but penetrates deeper providing energy for the shaded leaves and signals lower growth to stretch for the light.
But hey, don't hate on red, it has signalling values of its own, such as flowering/fruting acceleration/initiation.
And on, and on, and on it keeps going...... :D

:passitleft:
 
If you want to talk about just efficiency, the Luminus COBS are the best on the market, at 2.37 JPW ran at 50W, per cob.

So, watt/per $, is definitely In Luminus above ALL.
 
PurpleGunRack said:
Sorry to be the buzzkill, but grams per watt comparisons only makes sense with clones grown in the exact same way with only different light sources, and to get acceptable statistical data it has to be repeated many times.
Opinion and subjective experiences hold little weight in scientific questions :Namaste:

GPW really doesn't mean anything since we're not including strain/pheno, gardening skills, veg time, growing method and turn around time in the equation, nor does ot say anything about % of cannabinoids obtained, which is one of the things more light gives you more of than increased dry weight of the herb.

I'll try to paint a few ''pictures'' explaining it.

A landrace sativa vs. a highly stable hybrid like Northern Lights in exactly the same setup will grow differently and yield very different resullts.

A SoG grow vs. one single big plant could get you the same GPW, but the SoG grow would do it 2-3 times faster than the big plant.


If you like keeping stats on yield, the two key performance indicators are g/m2 per day and total price per g (including all electricity used, nutes, medium, seeds/cost of keeping clones and mothers etc.)
-----------------------------------------------------------


The answer can be short and sweet, and have high probability of being true at the time of this being posted = Samsung LM301b middle power diodes.

NB! If you just want a bang for your buck and good lighting for full cycle growing and don't care about light science, just get +600 diodes (+900 for full saturation) in 3000K per m2 (10,8 sq. ft.) running at 60-80%, and stop reading now :D


Or the answer can be windy, abstract and vague at best, but without any statistical margin of error :)

In reality, measuring the actual photosynthetic efficiency of a light is a very complex task, and is not possible to do with the knowledge and technology currently available.

To break it down, plants respond in a variety of ways to different wavelengths, and timing and the lenght of exposure of said wavelengths.
There's both a photosynthetical value and a signalling value, ie. Far Red (730nm) creates almost no photosynthesis but accelerates photosynthesis of other wavelenghts and can be used to signal the plant to go into respiratory mode by havaing a few far red diodes on for one hour before lights out to 15 minutes after lights out, this will makes the plants ''think'' the night is longer and make it accelerate its fruiting process.

How to combine wavelengths, intensity and timing perfectly to a single phenotype alone is a study of several life times.



We can easily compare electrical efficiency of light sources of the same type and CCT using lumen per watt.
It doesn't say anything about the photosynthetical efficiency, but it's a fine guideline for output of light.


The best practical way is to use a proper quantum sensor (400nm to 700nm) and measure the PPFD at several points (center, sides and corner of every sq. foot) on given area, with the light from different distances from the surface each time.

However, PPFD does not take the photosynthetic value of the lightwaves in this range or the signalling value of any of the lightwaves into consideration.
Blue lightwaves in the 440-480nm range are a lot less photosynthetically efficient than red light waves in the 640-680nm range, but blue has effect on lateral branching, stretch, resin production and a much more.
Green lightwaves are less efficient than red and blue, but penetrates deeper providing energy for the shaded leaves and signals lower growth to stretch for the light.
But hey, don't hate on red, it has signalling values of its own, such as flowering/fruting acceleration/initiation.
And on, and on, and on it keeps going...... :D

:passitleft:
Click to expand...

I intend to do that scientific test. I have my grow perfected so that things don't change. I will make the switch to half leds and see how it goes. I'm trying to find the best solutions first and see what the community has to say.

I'm trying to find exactly the most value of gram per watt not total cost of a gram. This thread is about finding the most efficient way to light a up a growroom. I know there are a lot of ways to grow but this is focused more in SOG and SCROG because those are the most efficient ways to grow. Also more focused on high yielding short indicas / hybrids because if you are taking space in your growroom growing malawi then in my opinion it's not worth it. Take them outdoor if you can and you are due to find something not even the best light would do. Don't take me wrong, you are right in everything you said above.

One thing you mentioned, do you believe LED's finish plants later than HID's?

............

"The answer can be short and sweet, and have high probability of being true at the time of this being posted = Samsung LM301b middle power diodes.

NB! If you just want a bang for your buck and good lighting for full cycle growing and don't care about light science, just get +600 diodes (+900 for full saturation) in 3000K per m2 (10,8 sq. ft.) running at 60-80%, and stop reading now"

You just gave me an idea to create a new thread, I will comment there and drop the link here later.

I see lighting science is a complicated subject and you briefly explained why. Which company, in your opinion, is on the forefront making those scientific studies?
Most of the big companies that have the resources seem not to care a lot about it. Samsung seems to be going in that direction but everything is new ( Samsung Electronics Begins Offering LED Component Solutions for Horticulture Lighting ). Phillips seems to bite the dust in terms of efficiency but what's your opinion on these ones? GreenPower LED flowering lamp - Philips Lighting
Since some companies have HID's for horticulture are you aware of LED research being carried out?
 

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