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Re: Lights & Tomatoes

Square Foot Gardening List - http://www.flinet.com/~gallus/sqft.html

How interesting. We just happened to have a light meter down in the basement
and I went to see what my fluorescents were putting out, in the centers it
was up to 1400 fc, at the ends down to 400 fc. My bulbs are mostly 2 or 3
years old, though I replaced 3 of the 8  this year. I can't wait to play
with this outside tomorrow. I also can't believe the engineer in the family
didn't realize the gardener in the family would appreciate this tool.

Tom
Portland OR,  Zone 8
http://www.teleport.com/~scut/garden.htm
-----Original Message-----
From: Bill <OOWON@netscape.net>

Here's a VERY shory excerp from a post I did on light for my OT Garden
group.
Notice athe right up on the bulb (2" is normally a recommended distance) the
light is 2/5 of direct sun, sometimes 2/10.

Florescents typically yield abot 5 candles per square inch.
At 1 .375 dia, that's about 200, in^2 per tube.
200fc x 5fc/in^2 x 2 tubes is 2000 fc per shoplight.

Moonlight, 0.02 fc.
Street light, 0.6 - 1.8 fc.
Daylight at a N. Window, 50-200 fc.
Office light, 70-150 fc.
Outdoors in shade, 100-1000 fc.
(Shoplight, 2000 fc.)
Direct Sunlight, 5000,10,000 fc.

Some of this is Westinghouse copyright, some mine.


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