Light distance at professional facilities

RM3

Well-Known Member

WeedFreak78

Well-Known Member
Light spread and distribution, including penetration, is what matters. Adjust light height to get the best spread over the canopy while getting the needed penetration. Adjust according to plant size and conditions.

Most larger (5'+) plants I've seen, though few, didn't have dense inner foliage, so penetration wasn't as much as a concern. IDK if they were pruned out or not...
 

a mongo frog

Well-Known Member
I disagree with most i guess. Im more of a fan of light management, keeping then as close as possible without any damage to the plant. 1000 watt air-cool 14-20 inches works well for me. sometimes less due to I've run out of room. Every strain could be different and every gardening style is going to be different on what you do with the lights.
 

Alexander Supertramp

Well-Known Member
I disagree with most i guess. Im more of a fan of light management, keeping then as close as possible without any damage to the plant. 1000 watt air-cool 14-20 inches works well for me. sometimes less due to I've run out of room. Every strain could be different and every gardening style is going to be different on what you do with the lights.
You can over saturate a plant with light by keeping the lights too close. And this can occur without the plant showing signs of heat stress or bleaching. Still holding back the plant from reaching it's full potential and potency..The difference between good weed and killer weed.
 

Bubblegum31

Well-Known Member
The ones on the lift on the ground of the tent is vegetables and fruits. Thats why they are there!

Mj seedlings is above them
 

a mongo frog

Well-Known Member
You can over saturate a plant with light by keeping the lights too close. And this can occur without the plant showing signs of heat stress or bleaching. Still holding back the plant from reaching it's full potential and potency..The difference between good weed and killer weed.
Defiantly can get to close. All i stated was going as low as you can go without fucking up plants. Light management gets one super potent buds and great depth inside the canopy. Everyones light height will differ on their situation.
 

Bubblegum31

Well-Known Member
I have 6500k 125w cfl

I wanted to have it above the seeslings as they are getting stretchy!!
1459555365562-1470797242.jpg

So you tell me now what should I do!?
 

Arcadio

Member
Put a thermometer at 12" under ANY HID light, with a new bulb, and if it is below 100 degrees, I'll show you a picture of my dick (and get banned).
There is no reason at all to have a HID fixture closer than 2 feet, as the loss of lumens is negligible, the spread gets lost, and the heat will definitely fuck your plant. I keep my LED's 2' away due to the intensity of the light as it WILL bleach your top bud, guaranteed, and my MH/HPS never get closer than 32". It is just better for the plant, as they just want light, and it really doesn't have to be that intense to do a good job in a small area.. Ever seen good grows just using CFL"s?. Sure you have, and that should prove my point.
Yeah if you just have the light and thermometer it would be over 100 degrees. But if you have good airflow under the bulb as well as a powerful fan pointed at the bulb, AND a powerful A/C for the space then you see what happens then is you gain a certain amount of temperature control and trust me you can definitely keep a canopy below 80 degrees at 12 inches from a 1000W HPS. If you can't it's because your equipment can't not because it's impossible. It is definitely possible and I definitely don't want that picture. Temps are measured using several thermometers that hang at canopy level as well as an infrared thermometer to measure the leaves directly. You may be interested to know that the AC doesn't even work very hard to achieve 80F. Using the right equipment in the right way can do amazing things to control an environment.

Loss of lumens negligible? The inversed squared relationship between light intensity and distance from source shows that from 2 feet to 12 inches gives you a 400% increase in lux (lumens/m2) at canopy level. The loss of lumens is far from negligible you lose a lot of light by moving up the lamp.

Regarding the light spread, I said before to forget about the need to sacrifice light intensity for coverage (spread) and to just consider the phase where the plants aren't big enough to worry about that such as early to mid veg.

As far as cfl's go sure I've seen some good grows using just CFL's and I've seen some outstading grows using HID lighting. Not worth comparing those. I doubt than any professional setups (that are interested in producing the best possible quality) use cfl's. You know those laboratory style setups you see that produce top quality, medical grade, highest resin content type stuff, they DO NOT use cfl's. I'll bet anything that the best bud around is always from HID lighting and possibly LED's but I've never tried great stuff from LED's so I don't know if the hype is really true about the latest LED tech. And yeah I know good even great stuff can come out of CFL's but when you're talking about the best, there is a definite difference in the growth vigor and style all through veg and flower and the final results when comparing HID to CFL.

If the light intensity was so negligible then everyone would be using 250W HID's and saving tons of money on equipment and electricity. But it's not the case, assuming everything else is in spec it's a well known fact that a 1000W will not only cover a far larger area but will also produce larger, thicker and denser flowers than a 400W for example. Same can be said when comparing a 600W to a 400W. When talking about flowering the quality difference is not huge between different wattages of HPS because the light spectrum is very similar. But there's a big difference between HPS technology and CFL when it comes to growing fruiting crops. HPS lamps are actually engineered for fruit/flower development. The types of processes it uses to create light are much more energetic and more akin to the sun than a CFL. CFL's are best for growing non-fruiting crops which do well when shaded from the sun. Crops that need direct sunlight benefit greatly from the type of light given off by HID (high intensity discharge) lighting.
 

Bubblegum31

Well-Known Member
Yeah if you just have the light and thermometer it would be over 100 degrees. But if you have good airflow under the bulb as well as a powerful fan pointed at the bulb, AND a powerful A/C for the space then you see what happens then is you gain a certain amount of temperature control and trust me you can definitely keep a canopy below 80 degrees at 12 inches from a 1000W HPS. If you can't it's because your equipment can't not because it's impossible. It is definitely possible and I definitely don't want that picture. Temps are measured using several thermometers that hang at canopy level as well as an infrared thermometer to measure the leaves directly. You may be interested to know that the AC doesn't even work very hard to achieve 80F. Using the right equipment in the right way can do amazing things to control an environment.

Loss of lumens negligible? The inversed squared relationship between light intensity and distance from source shows that from 2 feet to 12 inches gives you a 400% increase in lux (lumens/m2) at canopy level. The loss of lumens is far from negligible you lose a lot of light by moving up the lamp.

Regarding the light spread, I said before to forget about the need to sacrifice light intensity for coverage (spread) and to just consider the phase where the plants aren't big enough to worry about that such as early to mid veg.

As far as cfl's go sure I've seen some good grows using just CFL's and I've seen some outstading grows using HID lighting. Not worth comparing those. I doubt than any professional setups (that are interested in producing the best possible quality) use cfl's. You know those laboratory style setups you see that produce top quality, medical grade, highest resin content type stuff, they DO NOT use cfl's. I'll bet anything that the best bud around is always from HID lighting and possibly LED's but I've never tried great stuff from LED's so I don't know if the hype is really true about the latest LED tech. And yeah I know good even great stuff can come out of CFL's but when you're talking about the best, there is a definite difference in the growth vigor and style all through veg and flower and the final results when comparing HID to CFL.

If the light intensity was so negligible then everyone would be using 250W HID's and saving tons of money on equipment and electricity. But it's not the case, assuming everything else is in spec it's a well known fact that a 1000W will not only cover a far larger area but will also produce larger, thicker and denser flowers than a 400W for example. Same can be said when comparing a 600W to a 400W. When talking about flowering the quality difference is not huge between different wattages of HPS because the light spectrum is very similar. But there's a big difference between HPS technology and CFL when it comes to growing fruiting crops. HPS lamps are actually engineered for fruit/flower development. The types of processes it uses to create light are much more energetic and more akin to the sun than a CFL. CFL's are best for growing non-fruiting crops which do well when shaded from the sun. Crops that need direct sunlight benefit greatly from the type of light given off by HID (high intensity discharge) lighting.
Well sayed arcadio.

Am still waiting for an answer for my poor seedlings needs!

not even a big plants.

Hope the guys above tell me what should I do for my stretchy seedlings as I believe that they are asking for more light appatently!!

Or am I wrong?
 

Arcadio

Member
You can over saturate a plant with light by keeping the lights too close. And this can occur without the plant showing signs of heat stress or bleaching. Still holding back the plant from reaching it's full potential and potency..The difference between good weed and killer weed.
So you are saying you can create sub optimal conditions by giving them too much light. How about the light output of the sun, you know how bright that is? In order to match the brightness of a summer day you need to get very close to a 1000W HPS. Less than 12 inches in my experience from measuring them both with a lux meter.

Now lets move away from lumens and lux meters and consider light power in Watts since
Lumens are a measure of brightness as perceived by people with the largest weighting by far being on the color green, a color which is more or less irrelevant to plants. Watts are better to consider than lumens when you are talking about the amount of light the plant can handle. Lumens are for humans.

In areas where cannabis has evolved to thrive the sun bombards with over 1000W per square meter of light power. That's huge. It is the equivalent of having inside a tiny 3ft by 3ft area, ALL of the power of a 1000W HPS in light (aka radiation) form. No losses due to heat.
HPS produce much more watts worth of heat than light to begin with so you'd need multiple 1000W HPS lamps on 1 tiny square meter to produce the light power that the sun does. That's a massive amount of light that they are used to handling and thriving in.
When you move an HID multiple feet away you are providing a tiny fraction of the light power the sun gives.

It's a misconception that HID lighting can be more powerful than the sun when it comes to lighting a garden because it definitely can't, the sun is way more powerful/intense. Can you imagine trying to getting 3 1000W HPS lamps into a 3ft by 3ft area and utilizing all that light with 100% efficiency (i.e. no light goes to sides) ?.........I don't think so. But that's what it takes to match the power of the sun. It still wouldn't quite match the sun because not all this light will hit the 3ft by 3ft area, a lot will go to the sides and top and be absorbed. And it wouldn't match it in penetration. The sun has ultimate penetration being the same intensity 1 km above ground as it is at ground level. The advantage we have indoor is light hours of course which might possibly be a reason to maintain far lower light levels in our garden than a nice summer day. But really that much lower???

Before arguing the validity of my claim about needing 3 1000W hps in a 3ft x 3ft area to match the sun go ahead and research the lighting power of the sun known as irradiance. Irradiance is a measure of solar power that only considers light power and it is widely accepted to be over 1000W per square meter at the equator and well above 900W anywhere that high grade cannabis has evolved. It seems that in the highest grade cannabis evolved in regions close to the equator and at high altitudes which are the places with the greatest light power and intensity.

When you talk about a 1000W HPS light fixture it is not a light that produces 1000W of light. Not by a long shot. It gets the 1000W name because it merely consumes around 1000W of electrical power via the outlet, usually a tad more. What it produces is just a couple of hundred watts worth of light and the rest is 800W worth of heat. That's why you'll notice that a 1000W HID lamp with the ballast will produce about the same amount of heat as an 800W heater.
If you are thinking about arguing about my claim of an 1000W HPS producing only a couple of hundred watts of light you should know this, even the most efficient laser in the world is only about 35% efficient at producing light meaning that 1000W of this laser would produce 350W of light and 650W of heat. That's just the way it is when it comes to converting electricity into light. You create mostly heat and a little bit of light.
HID's are far more efficient than CFL's though.

Should we be striving to match the sun. Our lights are already at a great disadvantage it terms of light output, spectrum and penetration even for the 1000 watter. So why would we be wanting to widen the margin by creating even dimmer conditions??
Perhaps it's simply because we give them so many hours of light but I find that it doesn't justify it. There are many places that receive over 18 hours of daylight with many hours of very bright and powerful sunlight.
And one thing I know for absolute sure is that when growing outdoors in the sun, the more light the better. The longer the days, the better. The clearer the sky, the better. It really does seem like that plant just wants that enormous 1000W per square meter of light raining down on her all day. An amount of light that you will not even get close to without frying your plants with all the heat created by HID. So if the plants aren't being fried, and in fact are at IDEAL temp with an HID at 10 inches there is absolutely no way in hell that the amount of light is more than the sun or even close.

Shit I'm explaining this to my self now. I just realized something that seals the deal for me. An HID should definitely become a heat issue before it becomes a light issue. Why?? Because of the simple fact that it creates a lot more heat than it does light.

Less than 20% light more than 80% heat...I wonder what will become a problem first?
 
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