Orchid light requirements in lumens?

[Roey.P.]

For a 29on 75cm shelf 88cm high
Can someone elaborate to me what low, medium and high light are in lumens. Got;

1. T5 bulb 22.5w 4000k cri 80 1600 lumens white 55cm.—can fit
2. T5 bulb 27.9w 4000k cri 80 2600 lumens white 115cm.-to big
3. T5 bulb 54.1w 6500k cri 80 4100 lumens white 115cm.-to big
4. T5 bulb 22.5w 6500k cri 80 1600 lumens white 55cm. - can fit got 2.
Can you suggest me which is better how far to put it from the plants. Should I get 2700k too for bloom? Is there anoyher cheap and useful bulb too try? T8 is reducing fast and too big anyway gor me. Thank you all!

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[WhiteRabbit]

[Mainwaring]

maybe something like this is better then T5 tubes?

http://www.ledlightsorient.com/30w-s...5tg-p-102.html

[Roey.P.]

Look nice but I like to know first the light intensity my orchid needs... I did a mistake once bought unworthy lamp...

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[Ray]

A lumen is not a unit of intensity, it is a unit of light flux. The intensity units we commonly see are foot-candles (lumens per square foot) and lux (lumens per square meter).

When you read that a T5HO bulb has an initial output of 5000 lumens, that tells you how much light is being emitted by the entire surface of the bulb, but it tells you nothing about what's hitting the plants, as that is determined by the quality and shape of the reflector (otherwise none of the light leaving the "back" of the bulb will reach it), and the distance from lamp to plants.

[Roey.P.]

I see thank you ray. So I am going to measure by foot candle is 1400 f.c. Is good enough for phals, dendrubiom and oncidiums. Also if y now the kelvin 2700 3000 or 6500 is the wave light in nm will suite the plant or I must by a special for plants light?
Thank you!


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[Ray]

In theory, 6500K is supposed to mimic the spectrum of mid-summer sunlight at noon on a cloudless day. The problem is that in fluorescent and LED lamps, it is a correlated (or corrected) color temperature, that is, designed so it LOOKS LIKE that to the human eye, rather than truly mimicking the spectrum.

If it is a plant light, then the chances are better that it will be good, but I don't think it's as critical as most think.