OK, probably not edible, but: I'm starting some impatiens from seed, the new disease-resistant "Imara SDR" and online instructions say they don't like too much light, though do need light to germinate. I've started using LED grow lights- more light for the watt- and they're MUCH brighter than fluorescent grow lights. I notice that basil isn't happy with that much light, so I'm trying a dimmable version. (Aside for the geeks: the LEDs are in a series string, and the power supply is constant current, so ought to be easy to dim; just add a variable resistor to the current regulator.) Does anybody know the proper lux value to do this, or will I just read the light level and tweak until the impatiens aren't loking bleached? TIA,
Impatiens Lighting question
Feb 08, 2021
Last reply: 5 years ago
2 Replies
LEDs are dimmable, yes, just not the way you describe it. They are basically made to blink really fast and the longer they are on vs off the brighter they appear. Putting a resistor in series with them would not only be wasteful but also will make them stop working - they require just the right voltage across the leads to light up. They do make dimmers for LEDs - get one of those. This one looks like it should work and priced reasonably
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(goes up to 100W, so you can control quite a few of those LED grow lights)
I've looked at the circuitry of a non-dimmable grow light: The string is powered by DC from a switching regulator that is sensing current output rather than voltage. I had no problem replacing a few 3-watt COB Leds with 5W (a little higher voltage drop), and measured current stayed constant. I'm really hoping someone has info on the proper light level for Impatiens. Thanks, all!
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