Why are so many new growers choosing blurple/led over hps/mh??

Lpena007

Well-Known Member
Price. And at no point will I be a commercial grower. Just a small closet will do me. I Couldnt justify spending alot of money when in the end I'm happy with an oz ya know. I grow for,myself and I'm not a heavy smoker. So 60 bucks for a light that works well for me .why would I go bigger?
What light do you use?
 

Lpena007

Well-Known Member
I did my homework long before i attempted my first grow.My actual first run was a window grow (which was low yield but successful) I was going to go with a blurple light but then discovered cree cobs. The tech is developing so quickly its freaky. I was glad I bought a light that gave me a great spectrum of light and have had great grows ever since. Maybe I have been lucky. I do not think so though. Arming yourself with knowledge before diving in is so key to success.
What light do you use?
 

Dumbguyneedshelp

Well-Known Member

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PhatNuggz

Well-Known Member
FYI, that is NOT a blurple light, though it is close. Blurples have ZERO white light

I doubt you would do this, but you should have your finished bud tested

You better be wearing proper glasses or your eye site will be irreparably damaged


 

coreywebster

Well-Known Member
See that's where i'm not so sure.

You are absolutely right imo, that it's heat which generates the light. I would assume it takes the same amount of heat, to reach the same output and luminosity? (in theory)

My argument is efficiency. From what I understand it generally takes more initial energy to for the same output, using hps. Because the hid's are losing thermal energy faster.
This is where I do believe, part of the led argument is true.
One could argue it's because led's don't put out as much infrared energy. But this is precisely my point. Because that same amount of energy is being utilized differently in the led.
Imo, this is why quality led's generally have more efficiency watt / watt.

I know for a fact a 60watt led, compared to a 60watt incandescent is much brighter.
Also I realize incandescent is different, but you get my point.

HID is more efficient in my situation, because I don't need a heater for my space.
Im in the same boat as far as the heat argument. A light source has an efficiency and produces heat and light.
The argument is always "well all light turns to heat eventually" but I think its the misconception of the term heat in physics since heat can also mean work, which can be biomass in this instance.
That energy is only released as heat (thermal) when its burned (outside our grow room usually).

The other argument is always "energy cannot be created or destroyed" but again if one light can produce 1gpw and the other light of equal wattage can produce 1.2gpw then that extra biomass is the difference in the efficiency of those lights both in electrical efficiency and spectral efficiency from the point of photosynthesis. That is energy that was not converted to heat in the sense of grow room temp rise.

Then we have the issue of different spectrums been absorbed by any material and different material warms at different rates depending on the spectrum.

Im sure a 60w incandescent would heat a space faster than a 60w LED. Then stick a plant in that space which will not really grow with the incandescent but will grow with the LED and the resulting biomass should reflect the difference to some degree between the temp rise of the two spaces.

What annoys me is the constant repeating of the same arguments without anyone proving one way or the other. I have seen it done at grade school level for basking lights (online) but unfortunately not done properly.

Im going to have to wait till one of my tents is free to compare a 400w HID to 400w LED and 315cmh to 315w LED. One way or another prove there is a difference in temp rise from ambient.

@cannabineer , I know your an educator, what are your thought? Keep it simple though dude, im not the brightest button in the box.
 

curious2garden

Well-Known Mod
Staff member
Yes, thank you. I guess that I did not make that clear. What I was asking was is if you have a infinite flat array if the intensity drops in direct proportion to the distance rather than the inverse square law because of the additive effects of all the point sources.
Good thought question about physics it added to my morning coffee discussion with Cannabineer. I'm sure he'll be around shortly.
Thanks!
 

cannabineer

Ursus marijanus
Yes, thank you. I guess that I did not make that clear. What I was asking was is if you have a infinite flat array if the intensity drops in direct proportion to the distance rather than the inverse square law because of the additive effects of all the point sources.
I pondered this. For a truly infinite array, each diode obeys the inverse square law. However this is precisely compensated by the fact that with distance, the the number of diodes visible to the plant (observer) rises as the square of the distance. This yields unity, so there should be no diminution of light intensity (at the observer) whether one was a foot, ten feet or a million miles away.

This is, however, a pure armchair thought experiment. In the real world, we use finite arrays, and these will always have an irreducible and nonzero adherence to the inverse square law of luminosity.

Annie and I had a conversation about this. It was illuminating.
 

cannabineer

Ursus marijanus
Im in the same boat as far as the heat argument. A light source has an efficiency and produces heat and light.
The argument is always "well all light turns to heat eventually" but I think its the misconception of the term heat in physics since heat can also mean work, which can be biomass in this instance.
That energy is only released as heat (thermal) when its burned (outside our grow room usually).

The other argument is always "energy cannot be created or destroyed" but again if one light can produce 1gpw and the other light of equal wattage can produce 1.2gpw then that extra biomass is the difference in the efficiency of those lights both in electrical efficiency and spectral efficiency from the point of photosynthesis. That is energy that was not converted to heat in the sense of grow room temp rise.

Then we have the issue of different spectrums been absorbed by any material and different material warms at different rates depending on the spectrum.

Im sure a 60w incandescent would heat a space faster than a 60w LED. Then stick a plant in that space which will not really grow with the incandescent but will grow with the LED and the resulting biomass should reflect the difference to some degree between the temp rise of the two spaces.

What annoys me is the constant repeating of the same arguments without anyone proving one way or the other. I have seen it done at grade school level for basking lights (online) but unfortunately not done properly.

Im going to have to wait till one of my tents is free to compare a 400w HID to 400w LED and 315cmh to 315w LED. One way or another prove there is a difference in temp rise from ambient.

@cannabineer , I know your an educator, what are your thought? Keep it simple though dude, im not the brightest button in the box.
I think you have it essentially correct.

Heat is energy, and this is stored as chemical potential energy in the biomass. How much biomass you build has to do with the usable PAR energy the light emits toward your canopy. The rest of the heat, and the light that is converted to heat, is waste. Even more annoyingly, it needs more energy (fans, coolers) for the grower to dissipate the heat.

Bottom line: the listed wattage of a light and the effective plant-building power are a function of the efficiency of the transducer (the hardware that turns one sort of energy into the other). And photon sources today have this efficiency ladder: incandescent <fluorescent < HID < LED.
LED is currently the most efficient watts electric → watts PAR transducer we have.
 

curious2garden

Well-Known Mod
Staff member
I pondered this. For a truly infinite array, each diode obeys the inverse square law. However this is precisely compensated by the fact that with distance, the the number of diodes visible to the plant (observer) rises as the square of the distance. This yields unity, so there should be no diminution of light intensity (at the observer) whether one was a foot, ten feet or a million miles away.

This is, however, a pure armchair thought experiment. In the real world, we use finite arrays, and these will always have an irreducible and nonzero adherence to the inverse square law of luminosity.

Annie and I had a conversation about this. It was illuminating.
The limitation in that system is distance from the source which equates to time :bigjoint:
 

Dumbguyneedshelp

Well-Known Member
FYI, that is NOT a blurple light, though it is close. Blurples have ZERO white light

I doubt you would do this, but you should have your finished bud tested

You better be wearing proper glasses or your eye site will be irreparably damaged


Ooooo i get it. The blue and reds. I've wondered. I'm like more of a pink then a Blurple.and what do ya mean by tested. Idk what ya mean exactly
 

Horselover fat

Well-Known Member
Yes, thank you. I guess that I did not make that clear. What I was asking was is if you have a infinite flat array if the intensity drops in direct proportion to the distance rather than the inverse square law because of the additive effects of all the point sources.
If it was indeed infinite (and in vacuum) then the photon density wouldn't drop... me thinks.

Look how HID lighting is used in agriculture. The lights are high up, but lots of overlapping light cones which produces an even photon density on the plants. They don't lose intensity, because photons don't disappear... they just spread out on a larger are. It's a little different in small areas, because we have to deal with losses due to the light reflecting off the walls.
 

PDRCanada

Active Member
Read most of this thread....dont know why.

I started in the 90s......BC big bud.
Couldnt get pre mixed back then, had to triple beam the nuits one at a time.
30 yrs ago we produced 8lbs under 2 vertically hung 1k hps/mh.
Cost wasnt a factor as lbs were selling to the states for over $3K.
Pretty cool huh....but that doesnt mean anything. I knew others that were
growing same clones, same set up and getting way less....

Thats why this debate truly is ......dumb.

No one here can conclude my type of light is better than yours.
Its environment, technique, tweeks and just having the talent that for
many will bring huge differences even with the same lighting let alone
trying to compare different types.

Look up "bias"
look up "sighted bias"

Tests that were made on weed would have to be under strict control
and to get true results comparing different grows they would have to
be conducted as "Double blind" or as an "ABX comparable"
So THC levels, Terpene level, CDB......all of it is BS.

In other words the people that do the testing wouldnt know whos
product they were testing or comparing. Even the people bringing them the
samples to test couldnt know.

Its why I laugh everytime I read the percentages on the containers they sell
to us up here in Canada.

As soon as the tester knows the client and $ has changed hands.....the testing is skewed.
 

printer

Well-Known Member
If it was indeed infinite (and in vacuum) then the photon density wouldn't drop... me thinks.

Look how HID lighting is used in agriculture. The lights are high up, but lots of overlapping light cones which produces an even photon density on the plants. They don't lose intensity, because photons don't disappear... they just spread out on a larger are. It's a little different in small areas, because we have to deal with losses due to the light reflecting off the walls.
I think you have it. We don't need a infinite array but it gets rid of worrying about the edges and . If we have a greater horizontal distance between the ends of the array as compared to the distance to the canopy I think it would be linear rather than the inverse square law. Would take a lot of led strips, not an economical purchase but might be in terms of electrical usage. I have been thinking about it as compared to a single bulb or cob. Mind you adding reflectors or lenses can change that pattern.

I have some seedlings in my starter tray/dome and I put two 5000k 11W 850 L bulbs in fixtures next to each other. They are sitting right on top of the dome with the seedlings right below. Because of the fixtures the two sets of plants right under the bulbs get the most direct light, the two in between these four get the light from both lamps. They seem to be just as happy as the other four. Which is a good thing these are to be my mothers. I was unsure if being this close to the lights will harm the plants, they seem to like it.

Which reminded me about the second question I thought way back when we were comparing dicks. I do have a cheap burple cob with integral driver that they are selling cheap now, I want to compare it to Leds with a 5000k temperature of equal wattage. That will come when I take clones off these mothers. I know the whole Beta compared to VHS argument was between burples and bulbs, but is there a comparison between burples for a full grow and, say 5000k Leds while the plants are in veg? I plan to use 5000k lights till they are flipped to flower then I would go to 2700 and 3000k Leds.
 
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