I don't understand all these lighting inconsistancies

[vintner]

The following are two exerps from the "Marijuana Growers Handbook" by Ed Rosenthal. Which can be found on the last page of this section of the forums.

Light requirements vary by variety. During the growth cycle, most varieties will do well with 1000-1500 lumens per square foot although the plants can usemore lumens, up to 3000, efficiently. Equatorial varieties may develop long internodes (spaces on the stem between the leaves) when grown under less that bright conditions. During flowering, indica varieties can mature well on 2000 lumens. Equatorial varieties require 2500-5000 lumens. Indica-sativa F1 (first generation) hybrids usually do well on 2500-3000 lumens.

To maintain a fast growing garden, a minimum of 20 watts of fluorescent light per square foot is required. As long as the plants' other needs are met, the more light that the plants receive, the faster and bushier they will grow. The plants' buds will also be heavier and more developed. Standard straight-tubed fluorescent lamps use 8-10 watts per linear foot.

Then I read in more recent posts that 50 watts/sq ft is the min you want to have. Who do I beleive?
Vin

 

[snugglefunked]

The following are two exerps from the "Marijuana Growers Handbook" by Ed Rosenthal. Which can be found on the last page of this section of the forums.

Light requirements vary by variety. During the growth cycle, most varieties will do well with 1000-1500 lumens per square foot although the plants can usemore lumens, up to 3000, efficiently. Equatorial varieties may develop long internodes (spaces on the stem between the leaves) when grown under less that bright conditions. During flowering, indica varieties can mature well on 2000 lumens. Equatorial varieties require 2500-5000 lumens. Indica-sativa F1 (first generation) hybrids usually do well on 2500-3000 lumens.

To maintain a fast growing garden, a minimum of 20 watts of fluorescent light per square foot is required. As long as the plants' other needs are met, the more light that the plants receive, the faster and bushier they will grow. The plants' buds will also be heavier and more developed. Standard straight-tubed fluorescent lamps use 8-10 watts per linear foot.

Then I read in more recent posts that 50 watts/sq ft is the min you want to have. Who do I beleive?
Vin

how bout both? ed rosenthal isn't stupid... take note that he says 20w per sq ft is MINIMAL!!! 50w/sq ft is just ideal... and you know what? you can still use more lights with good results... 50w/sq ft is not minimal... just what you want to strive for...