I know for plant biology that the ammount of light can be too much for certain plants. Good example is Melissa officinalis. Too much light changes the color of the plant to purple wich is cool thought. Grows natural and green if kept behind a window but turns purple already under 21W 6500K CFL(1300 lumens/lux).(tested this myself)

But for cannabis being grown naturally in deserts near the equador. High concentration of light would also need high concentration of other components needed for fotosynthesis?

If i had a laboratory i would be runing tests for diffrent combinations of light+nutrients+Co2+dark time.

Natural co2 levels are around 300 ppm ? and natural light is
10,000â??25,000 lux Full daylight (not direct sun)[2]
32,000â??130,000 lux Direct sunlight
(copied from wikipedia)

lets say we want to simulate best outdoor conditions inside we would need atleast
25000-35 000 lumens per square feet of plants.
We would need to match the nutrient usage at this intense light levels correct?
Lets keep in mind that man made light does not match the full spectrum of light gained from the suns rays.

So maby just maby only one type wavelenght of light could be too much if high enough concentration right ? can anyone confirm this ?
hcmake Reviewed by hcmake on . Who likes numbers? Alright I've been researching, brain storming, tokin', and drinkin', trying to figure out how to put my lighting system to it's optimum use. I'm working with a 1,000w HPS system. Thats with a MH conversion bulb, and eye hortilux HPS bulb I've figured the numbers with 3 possible garden sizes 4x4, 4x5, 5x5. I'll start with the brightest. 4'x4' area=16 square feet or 62watts/ square foot HPS=9,062 Lumens/ square foot MH =6,562 Lumens/ square foot 4'x5' area=20 square feet or 50watts/ Rating: 5