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View Full Version : What's the optimal watt count per square foot?



maspino1
10-19-2007, 08:52 AM
My homegrown box puts out a total watt output of 107W/ft.² from 3x125W CFL.

This is a CFL grow. I want to know if this is overkill since I've mylared
every surface inside the box so that should increase efficiency as
well as penetration. I know it should be 50W/ft.² so please tell me if
107W/ft.² is too much because even if I removed one light I'd still
get a total output of 71.43W/ft.².

Any advice from seasoned farmers would be nice of course.


Thanks :)

MISC:
1xSATURN dual-spectrum from EZHydroKit (6500k+2700k) for vegging.
Then I will add 2xHydrofarm Envirolites (2700k).

maspino1
10-19-2007, 10:32 AM
Oops, I forgot to mention. The total floor space in my box is 3.5ft² and stands 34" high.

In reality it's really 3.2 but I put it to .5 so it'd be easier to calculate.

the image reaper
10-19-2007, 10:54 AM
I believe it was Mel Frank's growing guide where I read that anything over 60 watts per square foot is wasted, the plant can't use it ... but, I usually hear growers claiming there is no limit to the light you can throw at it, so, be prepared for a lot of variation in these replies ... :smokin:

rhizome
10-20-2007, 10:28 PM
Umm- that 50w per sq. ft. rule refers to 50w of HPS, based on the output per watt of a standard 1000w hps in a magnetic ballast.




Remember, wattage per square foot is a metric of power consumption, not brightness.

maspino1
10-24-2007, 05:56 AM
ok, i've never heard of a watts/sq. ft for cfl
is there one that you know of?

Eclipse1203
10-31-2007, 11:13 AM
40W per square foot is fine...But remember that lights intensity decreases exponentially as the distant from it increases from the plant so it is better to use more than what the plant requires as the plant may not be getting the amount of light you think.