Quote Originally Posted by Alaric
When I take my light meter and measure sunlight intensity at noon on a clear summer day-----around 10,000 fc (footcandles). That's true wheather standing atop a tall building or on the ground.

18" directly below my hortilux 1K hps is also 10,000 fc------now another 18" farther below is only around 2500 fc-------yep about 1/4 from the previous point of measurement.

And yes Virginia----I've found that plant material exposed to intensities much higher than 10K fc start bleaching-------and not from heat.

So what this means to me is-------we have a very small envelope of useable light intensity from HID lighting.

Things to do:
1) keep your canopy flat or concave with tying branching down, trellising, or whatever.
2)light movers are great----- especially in the aero/hydro world where moving plants around is not practical.

cheers,

Alaric
Damn, that makes it sound only practical to have plants up to about 2.5 feet tall. That means my dreams of having 8 foot + tall plants is gonna require a ton of supplemental lighting on the lower branches to get em' big without sacrificing quality.
Back to the drawing board, and I gotta pick up a ton more flouros than I hoped. Fuck it, good things require the extra effort!
peace
davejohnwright Reviewed by davejohnwright on . Anyone have a formula for.... Anyone have a formula for loss of lumens due to distance? I found one that I'm not quite sure about. Rating: 5