1 day away from 3 weeks into 12/12 cycle:
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1 day away from 3 weeks into 12/12 cycle:
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Generally, for flowering which is better to use?
2275 lumens (luminous flux) OR 1500 lumens (luminous flux)
anon you need to think of light intensity in terms of density. In other words, lumens/ft2 . Lumens by themselves don't mean anything if you don't know how much physical space they are spread over. Figure out the square footage of your area under the light, then you can determine light density. My 2cents is minimum of 2000 lumens/ft2, optimal 5000-7000 lumens/ft2.
I am using 3 CFL bulbs at 1500 lumens EACH BUT I will be changing them to bulbs which have 2275 Lumens EACH.
The results for the light intensity of my grow box:
Square Footage Under Light Source = 4 Square Feet
Formula: lumens/ft2
1500/4 = 375 x 3 = 1125 Lumens
2275/4 = 568.75 x 3 = 1706.25 Lumens
minimum of 2000 lumens/ft2, optimal 5000-7000 lumens/ft2.
So according to your formula i need 20,000 Lumens? Thats hell of a lot...
5000 lumens/ft2 is the figure I see all the time as the minimum for optimal flowering. The data on lighting is bewildering and everyone seems to have their own ideas. I'm just regurgitating the common info that I've come across. Also I don't use cfl and things may be different when using that kind of light. The other variable here is distance from the light source, closer=more lumens. When people rate a bulb by lumens I believe they are measuring at 1 ft. distance. Hopefully someone with more experience with this (esp. cfl) will answer. But you should google it. There is a ton of info about this out there. Also the Grow FAQ on this site discusses this.
Also anon there are other variables involved, so I think these figures are guidelines rather than firm rules. I have my plants spread out to about 25-30 ft2 with a total of 116,000 lumens that's about 4,000 lumens/ft2 which would seem too low, but I use two lights with overlapping light cones as well as light spreaders. My plants seem vibrant and healthy.
Quote:
Originally Posted by anon12
True dat!
However, those figures are for a more of a point source light like HPS and MH.
The advantage of CFLs is the fact that, like LED arrays, they are not point source lights.
We can have the plants much closer to the bulb and we catch a break on the inverse square law.
This time it works in our favor,
As you get closer to the bulb, lumens per square foot soars.
Go with the stronger light and select for color temperature.
I'd recommend that you use "warm" white for flowering.
Mo' red gives mo' betta buddage.
Carry on,
Weeze
Wasup Peeps:
Have some exciting news! Its has been 12 weeks and 1 day from the start of planting my seed until now AND 3 weeks 5 days from 12/12 cycle and my plant has officially begun the process of flower/bud growth. Its amazing and beautiful!
Here are some pics (let me know what you think please:
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