16k lumens HPS vs. CFL

ceestyle

ceestyle

Well-Known Member
moon47usaco said:
Of what field if i may ask... =]



Should that be lumens per cubic foot/cubic meter... ??

How would you get the square feet of a three dimensional growing area...??
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I'll just say I'm in the physical sciences and engineering.

Lumens per square meter is a metric of light intensity (lux), as it's only the area upon which light falls that is relevant.

These general rules of thumb are generally based on a horizontally mounted light or lights with a decent reflector over a number of plants. Of course lumens doesn't by any means describe how you distribute the light over the area, so obviously heuristics depend on your setup. I would imagine that most are made based on a need to distribute HIDs, so are probably best for that use.
 
DeweyKox

DeweyKox

Well-Known Member
Dam Cee, You so smart! I feel lucky you commented on my Dumb Journal with all my mistakes and trial and error problems. J/K But dam, I just learned allot!
 
moon47usaco

moon47usaco

Well-Known Member
ceestyle said:
I'll just say I'm in the physical sciences and engineering.
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Sounds like you work for the government... =] LOL... =]


Lumens per square meter is a metric of light intensity (lux), as it's only the area upon which light falls that is relevant.
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That makes more sense thanks... =]

I am already using 6 23W cfl lights in my grow box and was thinking of adding a small watt hps to the flower box... That info is most helpful as i design the locations for the lights... =]

Peace... =]
 
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Budda_Luva

Budda_Luva

Well-Known Member
ceestyle said:


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ok from what i was talkin about earlier with the reflector right above the HPS i dont tthink it would allow much light to reach the aluminum above it since the HPS relfector is in the way and cruved reflecting the light diferently than it would from the flat surface of the aluminum foil at the ceiling of ur box and wouldnt some of the from the CFL be blocked from the plants since the HPS reflector is in the way again juss som thoughts i really dont know how light intensity and the relations to reflecting light works but juss some shit that came to my head when i seen ur setup
 
ceestyle

ceestyle

Well-Known Member
n00b_marijuana_grower said:
ok from what i was talkin about earlier with the reflector right above the HPS i dont tthink it would allow much light to reach the aluminum above it since the HPS relfector is in the way and cruved reflecting the light diferently than it would from the flat surface of the aluminum foil at the ceiling of ur box and wouldnt some of the from the CFL be blocked from the plants since the HPS reflector is in the way again juss som thoughts i really dont know how light intensity and the relations to reflecting light works but juss some shit that came to my head when i seen ur setup
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The HPS light will not reach any mylar on the ceiling. It will reach the mylar on the sides, however.

There is a point as you bring the plants closer to the lights at which the aluminum reflector will obstruct some of the CFL light in the center. This is somewhat irrelevant, as you would not put your plants that close to the HPS.

As has been pointed out - first by me and then a couple others - you would ideally want the HPS farther away than the CFLs. It was done the way I have it because the CFLs were in place already. IN addition, a great deal of the CFL light will be reflected by the mylar, making their distance from the canopy less important.

I've been doing some work with reflector simulation, and a vast improvement can be made with a better-shaped reflector for the HPS.
 
ceestyle

ceestyle

Well-Known Member
It was at about 3 after I had been smoking on it for about a month and it was obviously well-cured. It was also probably two weeks premature, so I imagine I could have had 5 or more had I been able to let it get nice and ripe.
 
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techhead420

Well-Known Member
Respect out for doing the light mapping. I like to see this sort of empricism.

Lumens is kind out a poor unit of measurement for plant lighting. A pure red light source (say 650nm) is going to have a much lower lumens rating than a green light source (say 555nm) even though the actual photon flux density might be the same. The higher lumen green light in this case is going to have lower photosynthetic activity than the red light. This spectral distribution is my only critique of the testing.

I use micro Einsteins or micro moles (uMol) whenever I can for this reason but you need to know the conversion varaible between foot candles or Lux and uMol with different light sources. It does give a more accurate unit of measurement for the total amount of photosynthetic activity.

Foot candles
 
ceestyle

ceestyle

Well-Known Member
techhead420 said:
Respect out for doing the light mapping. I like to see this sort of empricism.

Lumens is kind out a poor unit of measurement for plant lighting. A pure red light source (say 650nm) is going to have a much lower lumens rating than a green light source (say 555nm) even though the actual photon flux density might be the same. The higher lumen green light in this case is going to have lower photosynthetic activity than the red light. This spectral distribution is my only critique of the testing.

I use micro Einsteins or micro moles (uMol) whenever I can for this reason but you need to know the conversion varaible between foot candles or Lux and uMol with different light sources. It does give a more accurate unit of measurement for the total amount of photosynthetic activity.

Foot candles
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Thanks.

Ya, we been all over this all over the place, maing.

https://www.rollitup.org/indoor-growing/83128-lumens-lux-adding-all-up-3.html

https://www.rollitup.org/grow-room-design-setup/42835-hps-mh-floros-phillips-cermamic-25.html

https://www.rollitup.org/grow-room-design-setup/74888-1550-watts-cfl-s-17.html
 
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techhead420

Well-Known Member
ceestyle said:
Thanks.

Ya, we been all over this all over the place, maing.

https://www.rollitup.org/indoor-growing/83128-lumens-lux-adding-all-up-3.html

https://www.rollitup.org/grow-room-design-setup/42835-hps-mh-floros-phillips-cermamic-25.html

https://www.rollitup.org/grow-room-design-setup/74888-1550-watts-cfl-s-17.html
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I like how you mention PUR in one of your threads. I've actually gone round and round about what spectral absorbtion chart is best to use. A lot of these fraud LED grow light manufactuers are using charts that only show absorbtion of various wavelengths of chlorophyll suspended in a solvent and even with charts showing total photosynthetic activity, as measured by the amount of O2 given off, a little digging showed that some of these LED manufactuers are using charts more appropraite for green algae rather than land plants.

$700 worth of LEDs, both 5mm arrays and custom built high power, has proven to be the biggest mistake that I've made in growing.
 
ceestyle

ceestyle

Well-Known Member
techhead420 said:
I like how you mention PUR in one of your threads. I've actually gone round and round about what spectral absorbtion chart is best to use. A lot of these fraud LED grow light manufactuers are using charts that only show absorbtion of various wavelengths of chlorophyll suspended in a solvent and even with charts showing total photosynthetic activity, as measured by the amount of O2 given off, a little digging showed that some of these LED manufactuers are using charts more appropraite for green algae rather than land plants.

$700 worth of LEDs, both 5mm arrays and custom built high power, has proven to be the biggest mistake that I've made in growing.
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The only real way to do it is to actually chart response for a given plant. This is essentially what PUR is. You can grow great tomatoes with a few fluorescents, but your pot would barely be smokeable.

I haven't looked at the light output of LEDs. Are they just weak, or is it the scattering on the way out?
 
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techhead420

Well-Known Member
ceestyle said:
The only real way to do it is to actually chart response for a given plant. This is essentially what PUR is. You can grow great tomatoes with a few fluorescents, but your pot would barely be smokeable.

I haven't looked at the light output of LEDs. Are they just weak, or is it the scattering on the way out?
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5mm reds are particularily weak; I used 3 different types of photo sensors with a digital storage oscilloscope because I had a hard time believing they were so weak. A lot more R&D has been thown into the 5mm blue LEDs, however, due to their being used as white LEDs. The 5mm LEDs simple do not have the photon flux density for good budding. I use them for mothers and clones, the lack of green light keeps the auxins levels down so the mothers will stay compact at lower light levels with the added bonus of lower starch levels so the clones root out faster.

The high power LEDs have future promise but they're just to damn expensive at this point. I experimented with up to a 15 watt LED (four 5 watt LEDs on the same die the size of a pencil eraser) but you need a large heat sink. I was once doing a high power test on a 15 watt LED and only had it pasted for a thermal bond to a heat sink but not actually mounted for a good mechanical bond. I accidentally yank the wires of the LED pulling it from the heat sink and literally under two seconds it started to smoke. :joint:

I've got nine 5 watt LEDs (2 blue, 2 white, 5 red) on a large heat sink that I've been messing with a constant current power supply but I've found that it isn't really more efficient that a CFL. The reds are 20% efficient, the blues are 16% efficient while a HPS is more like 35% efficient. The white LEDs, BTW, are to boost auxin levels- I think this is a major problem with LED grow lights on the market and why pot grown under LEDs without green/white take longer to mature since auxins play a vital role in budding but that's just a hypothesis; I've seen no white paper to back my claim up.

Maybe LEDs will be ready for prime time in five years of so as the quantum efficiency goes up and the price down but not at this point. They will not be replacing my 270 watt son-agro HPS bulb anytime soon.

BTW, I've found little difference in growth between 630nm and 660nm LEDs in veging.
 
ceestyle

ceestyle

Well-Known Member
techhead420 said:
5mm reds are particularily weak; I used 3 different types of photo sensors with a digital storage oscilloscope because I had a hard time believing they were so weak. A lot more R&D has been thown into the 5mm blue LEDs, however, due to their being used as white LEDs. The 5mm LEDs simple do not have the photon flux density for good budding. I use them for mothers and clones, the lack of green light keeps the auxins levels down so the mothers will stay compact at lower light levels with the added bonus of lower starch levels so the clones root out faster.

The high power LEDs have future promise but they're just to damn expensive at this point. I experimented with up to a 15 watt LED (four 5 watt LEDs on the same die the size of a pencil eraser) but you need a large heat sink. I was once doing a high power test on a 15 watt LED and only had it pasted for a thermal bond to a heat sink but not actually mounted for a good mechanical bond. I accidentally yank the wires of the LED pulling it from the heat sink and literally under two seconds it started to smoke. :joint:

I've got nine 5 watt LEDs (2 blue, 2 white, 5 red) on a large heat sink that I've been messing with a constant current power supply but I've found that it isn't really more efficient that a CFL. The reds are 20% efficient, the blues are 16% efficient while a HPS is more like 35% efficient. The white LEDs, BTW, are to boost auxin levels- I think this is a major problem with LED grow lights on the market and why pot grown under LEDs without green/white take longer to mature since auxins play a vital role in budding but that's just a hypothesis; I've seen no white paper to back my claim up.

Maybe LEDs will be ready for prime time in five years of so as the quantum efficiency goes up and the price down but not at this point. They will not be replacing my 270 watt son-agro HPS bulb anytime soon.

BTW, I've found little difference in growth between 630nm and 660nm LEDs in veging.
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Great post. It's refreshing to see information supported with facts and experience, and an ability to admit speculation. rep+

It's pretty surprising that the efficiency of such a ridiculously basic device like an HID could be anywhere near a solid-state LED. One can't help but think about vacuum tubes vs. the transistor, where there's obviously no comparison. I'm going to have to look into this a bit further ...
 
pacman123

pacman123

Well-Known Member
Where did you find 2700 lumen CFL's that fit into a vanity? I can only seem to find 1750! Who makes them?

Thanks
 
ceestyle

ceestyle

Well-Known Member
I found them in three-packs on ebay for cheap, but I've seen them at Ace Hardware and Home Depot ... Fry's had them too
 
E

erbium

Well-Known Member
IMO, using a combination of different lights and different spectrums is your best bet. There is no " 1 perfect light source". Be it different spectrum and size CFL's or HPS with CFL supplementation or even HPS up top and T5's of different spectrums on the walls and LED's filling every other spot.

Information like given in his experiment is valuable for figuring out what you need. Penetration AND the right spectrums are important so why not have them both?
 
ceestyle

ceestyle

Well-Known Member
erbium said:
IMO, using a combination of different lights and different spectrums is your best bet. There is no " 1 perfect light source". Be it different spectrum and size CFL's or HPS with CFL supplementation or even HPS up top and T5's of different spectrums on the walls and LED's filling every other spot.

Information like given in his experiment is valuable for figuring out what you need. Penetration AND the right spectrums are important so why not have them both?
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I think one of the most important take-home messages from this experiment is that your ideal lighting will totally depend on your individual space. Whether or not to use CFLs or HIDs, as it happens, is only a question in small spaces like the one in question here.

Probably the next thing on my agenda if I have spare time (IOW, unlikely to happen any time in the near future) is to address the myth that HID magically has better penetration. As I pointed out, light is light at a given color, so HID light doesn't penetrate any better than CFL light does fundamentally. Having one HID in the center, as opposed to one CFL flanked by several others having the total power of the HID, however, will result in better HID penetration due to increasing distance from the bulb for the flanking CFLs, but there are certainly cases where CFL will offer better penetration. It is another case of having the right light for the right space and canopy height/density.
 
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