LED UFO lights

[Kelo]

I wonder if I could glean some information form the more experienced grower as to the likelihood of this light being suitable for growing and flowering orchids. I feel optpmistic but friends have their doubts. Thank you.

UFO 135W

[littlefrog]

I'm going to be growing quite a bit under LED lights. And maybe even selling some... I like them.

Just fair warning, they aren't much fun to look at. At least not very long. But they seem to work at least on the things I'm testing.

[Kelo]

What do the plants look like? lol

[Ray]

As the lights are red and blue, there are no green wavelengths to be reflected back to the eye, so the leaves look more-or-less black.

Those are great for growing - assuming you have sufficient intensity - but horrible if you actually want to look at the plants.

[Kelo]

Ah, so I take it there has been little improvement in LED's over the years? I presume the blackness will apparent with more up to date LED's?

[DavidCampen]

Originally Posted by Kelo

Ah, so I take it there has been little improvement in LED's over the years? I presume the blackness will apparent with more up to date LED's?

You can get LEDs that emit green but green is not very useful for photosynthesis so it is wasted wattage.

[Kelo]

Mmm... it might be over-complicating things to add green LEDs for aesthetic reasons then.

[DavidCampen]

Originally Posted by Kelo

Mmm... it might be over-complicating things to add green LEDs for aesthetic reasons then.

You can always have other lights in the room e.g. fluorescent to give you some green.

[littlefrog]

Well, I'm going into it whole hog, so I'll probably be posting stuff in a few months about setups and stuff. Actually half hog, I'm going to do about half LED and half fluorescent (T5).

You can buy white LEDs, although really it seems kind of dumb. For the price, I'd go with compact fluorescents (spirals) if you want white. Or regular long tubes. The benefit to LED is you use only wavelengths that are used by the plants. The reason plants are green (or mostly green) is that this is the wavelength that is reflected back at you. In theory, you can use a lower wattage and get the same amount of useful light, since you aren't blasting the plant with stuff that would bounce off anyway. Or, you can increase the wattage and drive the plants harder, without extra heat.

I did do a little experiment with a boring video a few months ago, you might be able to find it on the forum if you search for it.

Rob

[Kelo]

OK, thank you!