Light Distance Didn't Effect My Buds

Hey guys I just got through with a grow a few weeks back and here's what I got to say.

I used a 600 watt light with 30 watts of the blue spectrum. It's a growbright bulb. the light was air cooled and I placed it 8 inched from the tops of the plants. Suprised to say all my buds were the same size.

Given the lumens that depreciate over distance shouldn't my outer plants have smaller buds? I was really expecting huge buds directly under the light.

Here's the question. Does it really mattter if your light is 8 inches from the top verses 20 inches?

well my man a lot of people on ya wud be guessing if they give u an answer however u have just tried it and have the proof. nuff said im sure the intensity doesnt diminsh untill you move it back 24" but thats jus wat i read not wat i did

sweetsmoker said:

well my man a lot of people on ya wud be guessing if they give u an answer however u have just tried it and have the proof. nuff said im sure the intensity doesnt diminsh untill you move it back 24" but thats jus wat i read not wat i did

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You have a great point. Though most of what growers READ about growing indoors with lights say that lumens greatly diminish inch after inch and you would think lesser lumens would produce lesser or greater buds. But I guess that's not the case. I've seen monster buds with 2700 lumen compact fluroescents. Growing with a 95,000 lumen light you would think of huge buds closer to the source of light and after going 20 or so inches away on the outskirts you would think they're getting maybe 25% of that light and would be smaller.

$0.01: Light does diminish as you raise your lights however proper reflective material around the plant and behind the bulb can counter act the distance.
$0.02: Lumens are for human eyes, plants have a different photoresponse spectrum. In other words the amount of lumens a light has is irrelevant. Think, watts per nanometer instead.

Wow now that's something to think about. See everyone on here, even the experts, Al B Fuct even if u will always speak of lumens. If it's watt per nanometer then why don't people talk about that?

What plants use from light for photosynthesis is the wavelengths between 400 and 700 nanometers (blue to red spectrum). What exactly does this mean though? Time to do some searching.

its the P.A.R that is is important to the plants, it is this that the plants take in or 'see' if u like lumens is wat the eye sees, have a look on envirolites.com they will explain all

gardenman said:

Given the lumens that depreciate over distance shouldn't my outer plants have smaller buds? I was really expecting huge buds directly under the light.

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no... lumens aren't really anything worth measuring or considering. instead think in terms of intensity and wattage. Lumens is for comparing similar lamps side by side as in a generic 1000hps is like 130,000 (probably more like 110,000) and a hortilux agricultural is 155,000. Lumens don't really mean anything tho besides an arbitrary measure of quantity of light. It is basically a unit of measure which is standardized and used to determine quality of lightbulbs. Although CRI is probably a better way of doing that.


if you wanted to get fewer, and larger, buds you should prune the bottom branches off before they flower in order to focus the plant's energy on the main top colas. you can also prune to increase the quantity of top colas.

gardenman said:

What plants use from light for photosynthesis is the wavelengths between 400 and 700 nanometers (blue to red spectrum). What exactly does this mean though? Time to do some searching.

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400-700 is whats visible to the human eye.

Plants absorb a broader spectrum like 280 up to something. This includes UV put out by the sun.

Green light, however, is not used for photosynthesis (~480 I think)