LEDs: Need opinions current to 2019 technology.

[OrcishOrchids]

I'm looking for straightforward hands on experience growing orchids indoors without sunlight using only LEDs. Preferably LEDs of today rather than decades past. this is no longer a suspect/new technology so we should have some facts by now, but the internet is convinced I must be growing weed and I can't seem to find anything conclusive in the forum.

So here is my question:
What's the real difference between a WHITE led grow-light and a regular WHITE led light of equal watts/lumins? Why can't I use a 5000-6500k shop light?

For the sake of simplicity I am ignoring all the purple lights out there and focusing on white or white-ish lights, because the purple/pink ones give me migraines and ruin my enjoyment of the plants.

[Ray]

The LEDs will put more of the energy into light and less into heat than a shop light - more efficient for the same watts.

That said, warm white LEDs, not the cold white of the 5000-6500°K CCT chips, tend to emit a small amount of far red wavelengths, which enhanced growth and flowering.

[neophyte]

like Ray said, LEDs are more energy efficient than other forms of lighting.

far-red light is perceived by plants as an indicator of darkness, which causes their stems to elongate and their leaves to grow bigger. it also mimics a winter day (which has longer nights and shorter days), which may trigger flowering in winter-blooming plants.

when choosing LED lights, look for full-spectrum lighting sources. (cool-white, for example, doesn't contain as much red/far-red light). shop lights are often cool-white colors, which seem brighter to our eyes because they contain more blue wavelengths, which keeps us humans awake longer. however, for a plant, this is bad because their growth is strongly influenced by the presence of red and far-red light (mainly the ratio between red/far-red). so for a plant, a shop light may not be enough.

btw, if possible, I would just grow plants in natural, outdoor light. i grew radishes for a science project for a couple months using led lights and the electricity bill was horrifying. also, natural light contains all the wavelengths, and the length of day and night varies more, which can tell the plant what season it is (and when to flower). <- it would actually be very cool if you tested if this makes a noticeable difference. maybe in the summer you make the plants have 12 hours day 12 hours night, and then in the winter, you keep some plants on the 12/12 regimen and make some have 11 hours day and 13 hours night or something and do a comparison to see if they flower earlier (of course this is for winter-flowering plants).

[OrcishOrchids]

I live in an urban apartment with all windows facing other buildings so natural light is impossible.

I'm sorry, I should have been clearer, my question is between regular LEDs and those specifically marketed as grow lights, I'm not really interested in incandescents or florescents.

[Ray]

White LEDs use similar technology to fluorescent to produce light: usually a blue (occasionally a UV) chip is used to excite a phosphor on its surface which radiates a variety of wavelengths that combine to appear white.

Also just like fluorescents, the makeup of that phosphor coating can vary. That said, a true plant light should have a better spectrum for plants, but that does not mean that it's that much better.

I have used $150 4', 32W, Philips Greenpower Production Module LEDs containing white plus far red chips. I have also used $12 Cree 18W LED floodlights I purchased from Home Depot. They both work fine. In fact, the floods have more utility, because, by using multiples at different heights, I can tailor the intensity over a smaller area by simply adjusting the height. It's much tougher to do that with a 4-foot strip.

[OrcishOrchids]

Ok, thanks for the help. I will do a bit more research before buying my lights, but this will really help me narrow it down.
Thank you

[Goldmanman]

My pleurothallids do great with "full spectrum" LEDs that are more or less white. The blue/red LEDs give more PAR, but who wants to keep a tank that isn't fun to look at?

I use one SANSI 40W for my 2x1 tank, but plan to up the lighting.

I'd also recommend getting a light meter. Dr. Meter LX1010B for $22 is more than good enough for my purposes.