grow lights on trial
I
’ve spent a lot of time talking with
gardeners since publishing The
LED Grow Book, and the majority
ask the same question: are there any
good, published, side-by-side studies
comparing LED grow lights to HIDs?
The unfortunate answer is, no. One
reason for the lack of side-by-side trials
is that they are difficult to set up in a
way that allows the trial parameters
to be the same on both sides, without
one side unduly influencing the other
and thereby undermining the results
of the trial. Differences in power draw,
heat signature, light scatter and other
variables between LEDs and HIDs
make the execution of true side-byside trials difficult.
The former tests for how much can be
grown with the same wattage, and the
latter tests whether LEDs can use fewer
watts while maintaining harvest size. A
well-designed LED vs. HID grow light
trial should test both of these options.
Grow Spaces
Differences in power draw, heat signature,
light scatter and other variables
between LEDs and HIDs make the execution
of true side-by-side trials difficult.
Watts
One of the largest promises of LEDs
(light-emitting diodes) is you can use
less watts to produce the same harvest
quantity as HIDs (high intensity
discharges). With today’s LED grow
lights, it’s becoming generally accepted
98
Maximum Yield USA | April 2015
that 500-600 W of LEDs can replace
1,000 W of HID lighting. This presents
the first question when designing an
LED vs. HID side-by-side trial: how
many LED watts do you use—1,000 W
of HIDs vs. 1,000 W of LEDs? Or
1,000 W of HIDs vs. 500-600 W of LEDs?
The next big question when
contemplating a side-by-side LED
vs. HID grow light trial is how to
physically set up the trial. Will both
lights occupy the same area, or will
they be in separate physical spaces?
Everyone wants to see a side-by-side
experiment, believing that this physical
arrangement proves all the growth
conditions are the same. But there are
inherent problems with a side-by-side
trial, starting with the amount of heat )