Have a Merry LED Xmas from the Magic Box

M

munch box

Well-Known Member
weediscool said:
isnt it supposed to be like 2000 per plant?

gl with your leds
Click to expand...
I've never heard of that one about the 2000 LEDs before. What is your source? I know the minimum watts per plant should be 100 watts per plant. I'm not sure if that same rule of thumb applys to LEDs, but if that were the case, I would need 7 panels and/or bulbs per plant. (each bulb/panel pulls about 14 watts) panel=225 bulbs bud spolights=168 bulbs
 
McLovin420

McLovin420

Well-Known Member
what matters is the lumen output & lux that reach the plant. If it was all about watts 400 watts worth of cfls would do as good as hps. good luck with the led's
 
sgtpeppr

sgtpeppr

Well-Known Member
I say give it a shot and see how it works. I certainly think the more intense the light, the better, but I also like that with LED's you can be more specific with the wavelength. As LED's continue to get cheaper, I think that wavelength specific high lumen LED bulbs will become more popular. I would say with this setup you will grow an excellent plant, it just may take a little longer. I guess that's the real experiment.....how long??? I don't think it will be excessive. Only time will tell.
 
abudsmoker

abudsmoker

Well-Known Member
the bud looks like small cfl grown stuff watch n learn. i have yet to adopt led's


now the led flashlights are awesome
 
robbie82

robbie82

Well-Known Member
abudsmoker said:
the bud looks like small cfl grown stuff watch n learn. i have yet to adopt led's


now the led flashlights are awesome
Click to expand...
Whats that supposed to mean, I have seen some amazing CFL grow, some of which look just as good if not better than MH, or HPS systems. so I dont know what u mean by that bro.
 
McLovin420

McLovin420

Well-Known Member
munch box said:
exactly how much lumen and lux will reach a plant with LED bulbs mclovin
Click to expand...
That depends on the bulbs and how far you have the lights from the plant. To figure that out you would use the inverse square law. Simply divide the lumen by the distance squared or I= L/D^2.

I looked into LEDs to recreate moonlight so I'll use their lumen rating(4.1) to work an example

You said you have about 2000 LEDs so we'll say that you have 2 12" panels = 1000 lights per panel.
1000 x 4.1=4100 lm
If you have those lights 1 ft away they'll be getting 4100lm from each 12" panel

2 ft
4100/4= 1025 lm per panel

3ft
4100/9= 455.56 lm

4ft
4100/16= 256.25 lm

.1 lm = 1 lux

at least that's my understanding of calculating the # of lumen hitting your plant.
Good luck with the LEDs man, I'm really interested in them myself. :blsmoke:
 
Lord Dangly Bits

Lord Dangly Bits

Well-Known Member
McLovin420 said:
what matters is the lumen output & lux that reach the plant. If it was all about watts 400 watts worth of cfls would do as good as hps. good luck with the led's
Click to expand...
400 watts of cfls does not penitrate as well as 400 watts of HPS. at least in my opinion. I have done a whole crop with like 700 watts of cfls. the top buds where really nice, but none of the lower buds got very big at all. I am going to stick with my HPS lights for flowering. As for the LED lights I would only use them as an addition to my MH or HPS lights.
 
cloneup

cloneup

Well-Known Member
bottom line is lumens , grow whatever under whatever, the sun gives off 10,000 per sq. ft. of space, thats the rule of thumb i go by, figure it out, it will take months to do in cfl's, in what takes weeks to do wiff HIP, dont know why ppls still argue about it
 
alphabibbiddy boo boo

alphabibbiddy boo boo

Well-Known Member
thing is, you cant really compare watt or lumens from hids to leds, because the beauty of the leds, far as i know, i that they only supply light in the necessary wavelength ranges for growth (particular blues and reds, obviously). That said, 100 watts of blue/red for agricultural purposes coming from leds is going to be waaaaay more effective than 100 watts of "white" (or a huge mix of wavelengths) coming from hids, because the wavelengths that matter are only a fraction of the total lumen output. I'm looking in to leds myself, as they seem the most efficient, with so many less hassels. DEFINITELY keep us updated.. the thing I'm trying to figure out is the ideal amount of blue and red lumens for seedlings/clones, vegging and flowering.

stay up, let us know
 
T

T.H.Cammo

Well-Known Member
I was hoping somebody would get it right, if I read down far enough! Cheers for Alpha-bob-boo!!! Only about 20% of HID light spectrum is usful for plants (that's PAR light, Photosynthecally Active Radiation). That 20% is, mostly, made up of two narrow parts of the blue spectrum and two narrow parts of the red spectrum. These correspond to the four "spikes" you see in the light spectrum absorbtion graphs for Chlorophyll-A and Chlorophyll-B. To make a long story short - 80% of the watts you pump into your HID's result in wasted money! You are paying $100 to get $20 worth of useful light.

In the second place, the "Inverse Square Law" has nothing to do with LED's. The Inverse Square Law is only applicable to "point" light sources like a normal light bulb or a candle flame (where the light radiates in a 360 degree radius, in all directions). The nature of LED's, on the other hand, is that they are focused into a concentrated beam; like a spotlight. When you buy LED's, one of the specifications you look for is the "projection angle". The narrower the beam, the less light photons get "lost". That's why LASAR beams are so powerful - they don't spread out! There is a formula for figuring out light loss/distance for LED's but it is pretty complicated and it takes into consideration the "angle" of projection.

Third, and last. I'd just like to give my $.02 worth about watts, and lumens. The plant couldn't care less how many watts or lumens you are throwing at it! The plant only cares about how many photons of PAR light actually land in it's light receptors. Sorry if this is a little deep, but it's important! The actual amount of photons that are available to the plant is measured in micro-einstiens, not lumens.
Lumens are just a measurement of how bright a light appears to the human eye. Remember that 80% of HID light is wasted on plants? That's the same 80% that produces the highest ratio of lumens per watt. The human eye is more sensetive to green, so x amount of green light appears brighter than x amount of red light (or blue). In other words - green light, which is useless to plants, produces more lumens.
LED's produce light in a very narrow slice of the color spectrum, so by using just the right combination of colored LED's (measured by wavelength), virtually 100% of the light output is useful to the plant (PAR light) - as opposed to 20% for an HID. The bottom line is that LED grow lights look like puny little weaklings because red and blue light is not strong in the "Lumens Dept.". But the truth of the matter is that LED's produce concentrated PAR light.
Don't get me wrong, using lumens is very useful when dealing with "Wide Spectrum" lights like HID's or Flourescents. For example: all 400 watt Metal Halide bulbs put out "about" the same amount of lumens - that's how we come up with the "50 watts per square foot" rule of thumb. Once the "wrinckles" are all worked out of LED grow lights, I'm sure they will become more widely used and better understood. My interest in LED grow lights has been rekindled - I get really jazzed when I read a thread like this!
 
Paradox

Paradox

Well-Known Member
i remember people mentioning this before christmas. funny you actually tried it. i can see it working, but it will be so very hard to find the exact specs on the LED's you are using.

i'd like to know how it works cause i literally have thousands of LED christmas lights that use little to no power!
 
You must log in or register to reply here.
Top