I plan on topping it to keep the canopy wide. I am most concerned with getting an LED fixture that doesn't fully activate photosynthesis.

Granted I know that wattage isn't the best way to determine light output and quality of light but it is a good estimator.

Clearance height will be minimal so anything too high powered is likely going to cause adverse effects.

Is there a comparison for an LED light that produces 'full sun' lighting.

How much of a concern is sunscald with LED lights?

  • Sunlight is so intense, I doubt you will be able to find an LED that can cause sunscald :P. Please give the standard for what a 'happy' pepper plant is.
    – J. Musser
    Oct 2, 2014 at 21:29
  • mm.. yes. By happy I mean approaching it's desired optimal amount of sunlight. ie. A pepper plant could be grown by a window with mostly part shade but I would consider that pepper plant a little on the 'sad' side.
    – Enigma
    Oct 2, 2014 at 21:32
  • What do you mean by 'that doesn't produce adequate lighting'? Is there a level you have to stay under?
    – J. Musser
    Oct 2, 2014 at 21:35
  • Basically the low end of activating photosynthesis. This is a porridge temperature question. Too cold and too hot are not desirable. I reworded it for clarity.
    – Enigma
    Oct 2, 2014 at 22:27
  • On the low end, you will be simulating partial shade, and productivity will be low. You will need full sun equivalent to grow a steadily productive plant.
    – J. Musser
    Oct 2, 2014 at 22:30

2 Answers 2


Shade, in full daylight, is about 10,000 to 25,000 lux (1 lx = 1 lm/m2, or 1 lux equals 1 lumen divided by 1 square meter.) so assuming the plant will be in an area of about 1m2, and the average led light puts out 80-100 lumens per watt, you will want something in the 250 watt range.

It seems kind of bright indoors, but much less than that, and the pepper plant will rapidly decline. There will be no sun scalding.

  • For what it's worth, I'm looking at goo.gl/ai8ViI which runs a lot less $-wise. It doesn't look like as nice of a package as the one you mentioned however.
    – Enigma
    Oct 2, 2014 at 23:55
  • @Enigma: That should work also.
    – J. Musser
    Oct 3, 2014 at 0:00
  • So according to a light meter that 300W light I got outputs 500k lumens about 2 feet from the light.
    – Enigma
    Dec 2, 2014 at 23:29

I've never grown anything under a light, but I can chime in a little about LED light color which is measured in Kelvin. Typically (at least in the US) there are two colors of LED available:

  • 2700K (warm white) produces a warm, yellow light very much like an incandescent light
  • 3000k (cool white) produces a light with more blue that tends to feel a little more "clinical" and which appears to be brighter

There is also a 5000k (daylight) bulb that produces a light similar to daylight. I haven't had the opportunity to work with one, some I'm not able to make a color comparison. I'm also not entirely sure how it stands up again the old incandescent 'daylight' bulb.

  • LED growlights are usually measured in nm (since there are specific red and blue wavelengths desired with LED growlights), while ones that light a house may be measured in k, which may be a combination of wavelengths (which may or may not include any of the ones you want). Jan 6, 2017 at 1:55
  • Fluorescent growlights are often measured in k, though. 5000-7000 are commonly desired for vegetative growth. Lower color temperatures can be used for other stuff, like flowering (in theory) and preventing damping off (in my experience), although in my experience they help with growth, too, although the plants don't lean toward lower color temperatures as much. Jan 6, 2017 at 2:00

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