how can we not know how much light by now?

[desertrat]

of course there's lots of bad info on the net but this is ridiculous. half of the sources say 3,000 lumens per square foot while the other half says 7,000 or more lumens per square foot is the right answer for weed.

i always go with the higher number, but what about you?

sources that say 7,000 – 10,000 lumens per square foot


1. LIGHT COVERAGE: Stationary lights: One 400 watt bulb provides adequate light for 10 square feet of space. One 1000 watt light provides adequate light for 20 square feet of space. http://forum.grasscity.com/absolute-beginners/446508-ideal-conditions-grow-marijuana-list.html

2. It seems that the installation of one 600 Watt sodium lamp per square meter is enough to achieve the best results. http://www.budseed.com/rockwool3.html


3. How much light is needed?
The minimum amount of light required by marijuana plants is around 3000 lumens per square foot.. The ideal amount is somewhere around 7000-10,000 lumens/sqft,
.
https://www.rollitup.org/general-marijuana-growing/723-things-know-about-lighting.html

4. Current theory holds that the minimum amount of lighting needed to sustain growth is 2,000 lumens per square foot. Optimal is 7,000 to 7,500 or greater lumens per square foot.

http://www.scribd.com/doc/2522847/Marijuana-Cultivation-Bible


5. How much light do I need?
Cannabis is categorized as a high light plant. There are minimum levels of illumination required to insure compact plants. I have read that gardens can be successfully lit by as little as 2500 lumens/ft² when vegging and 5000 lumens/ft² when flowering. I have never used anything less than 3000 lumens/ft² for vegetative plants and 7500 lumens/ft² for flowering plants
http://www.themarijuanaforum.com/forum/showthread.php?t=280


sources that say 2,500 – 3,000 lumens per square foot



1. LIGHT 
Indoors, 2000 lumens per sq. ft. is about as low as you want to go indoors. 
2500 lumens psf should be a good target, and 3000 is optimal if your going to inject or enrich CO2 levels

http://www.marijuanapassion.com/forumWOW/Full-Marijuana-Growing-Guide.html#LIGHT



2. Lighting guide

HID Light Output Primary Growing Area
100 watts 2' x 2'
250 watts 3' x 3'
400 watts 4' x 4'
600 watts 6' x 6'
1000 watts 8' x 8'



http://www.greenmanspage.com/guides/lightguide.html


3. Guidelines
A 250 watt fixture will supply enough light to cover a 2.5 foot by 2.5 foot grow area.
A 400 watt fixture will supply enough light to cover a 4 foot by 4 foot grow area
A 600 watt fixture will supply enough light to cover a 5 foot by 5 foot grow area.
A 1000 watt fixture will supply enough light to cover a 6.5 foot by 6.5 foot grow area. http://www.a1b2c3.com/drugs/mjgrow4b.htm#A06

 

[Silky Shagsalot]

i didn't read all of your post, but i can tell you this. you can never have too much light! use as much as your area can handle. the only issue will be a suspiciously huge power bill, and handling the heat.

 

[desertrat]

i didn't read all of your post, but i can tell you this. you can never have too much light! use as much as your area can handle. the only issue will be a suspiciously huge power bill, and handling the heat.

yeah, i was just getting tired of all of the "how much light do i need?" questions.

 

[roka]

Yo... here's a cool chart that someone else had on a thread.

Cheers

 

[desertrat]

Yo... here's a cool chart that someone else had on a thread.

Cheers

roflmao that's my chart

 

[roka]

haha... cool... nice chart dude.