LED Light experiences (Help please)

Wolf, the problems are likely due to some factors other than light source unless it is the only light source. Are you sure it is really 550lm from 10W? It is worse efficacy than any known CFL bulbs (which don't have high efficacy in general). I'm not sure which light you are using, but when I search for "CAT emergency portable light", I don't see a one with 550lm specification. If it is really 550lm, and if it has a wide beam angle (e.g. 120 degree), you probably don't have enough light for Cattleya types. But I'm guessing that you have natural light as the main source and augmenting it with the artificial light.

 

First off turn the light all the way. Second, move it closer to the plants. It isn't doing anything at 2 feet away. Third, Cattleya Alliance things are tough. They can take the light and they'll be happier for it.

 

I still haven't found the spec for it, but from the photo, you have a switch to go between the high (1100lm) and low (550lm) output, right? If it is really 10W, and putting out 1100lm, it has a fairly decent efficacy for this kind of products. So nothing wrong with it (other than high price).

Since we don't know the beam angle, it is difficult for anyone to recommend the distance. Do you have a camera, and know how to look at EXIF data (i.e. aperture, shutter speed, and iso)? If so, you can use it to gauge the amount of light (check Ray's site here). But with the distance (16"-24"), you'll be using the high mode (unless it is a spot-light type).

For the alternatives, if you don't care about the electricity cost, LED PAR38 bulbs would be much cheaper than this emergency light. Or you can find LED shop light. Since you are growing mainly higher light orchids, you might need quite a bit. I'm not sure how big your grow area is, but it could be cheaper to go with higher efficiency ones if your electricity isn't cheap. If you have a fairly large area (4'x2'), something like this will cover it:
100 Watt Citizen CLU048 (2) COB Grow Light Kit
This is preassembled, so all you have to do is hang them up.

 

In this case the "PAR38" merely means the lamp is a Parabolic Aluminized Reflector lamp that is 38/8= 4.75" in nominal diameter. It has absolutely nothing to do with Photosynthetically Active Radiation, the amount of usable light the plant gets.

I'll make an editorial comment here: growing orchids is not the cheapest obsession we can have; if you're going to grow them, be prepared to give them what they want, and sometimes that can be costly.

 

LEDs do NOT put out enough energy.
They are very bright, but they are not capable of producing enough energy for a plant (because plants obsorb photo energy and produce an electron flow (kind of like a solar panel)).
Floressent tube lights work the best.

 

My seedlings will be quite surprised to hear that...

They're currently growing very well under LEDs.

I think Naoki's plants will be very disappointed to find that out, too.

 

As will mine - their only light source after selling my greenhouse was LEDs, and they are doing just fine.

 

It maybe okay for seedlings and lowlight plants, but for stuff like Catleyas, it's not enough.

 

I am very sorry for shuving my opinon down your throut's.
I sincerly apolagize for any missleading info I may have put out there.

I meerly said that because my plants get long and skiny, pale, and little growth.
I just do not want anybody else to have my awful luck.

Maybe I have not gotten the right type of LED lighting.
I will try again.

 

Edit: oops, I guess you posted while I was eating lunch. Just in case you want to know, I'll leave the following here.

Tong, your statements are a little too vague to be right or wrong. You are correct that 1x 1W LED won't have enough light for most plants. Obviously, if you put enough wattage (or energy), any light source (including incandescent light bulbs) can produce enough photons to saturate photosynthesis of any plants on earth. Well, if you use thousands of candles, you probably needs a good reflectors, and it would be tough to get enough from fireflies. LEDs can provide 10x the light intensity of sun if you use enough of it. Indeed, many people grow full-sun plants like Cannabis, Lettuce, Tomatoes, or carnivorous plants with LEDs.

Photosynthesis is more of a quantum process, so the number of photons are more important than the energy of photons. In other words, the number of photons is more important than the energy level of each photon (i.e. a bluish photon with lower wavelengths has a higher energy level).

It works ok, but if you care about the efficiency (and I do), I wouldn't use fluorescent lights any more. T8 (and T5HO) has about 0.84 micromol/J (in terms of photosynthetically active radiation, PAR). This value is the rate of number of photon produced for a given watt of electricity (i.e. efficiency). The cheap LEDs are pretty similar to T8/T5HO efficiency. Expensive commercial LED grow light (e.g., Fluence or Phlips green power, which Ray uses) can achieve around 2.2 micro mol/J. With DIY, the ones which Carl and I use give around 2.0 micromol/J for Phillips XF-3535L and 2.6 micromol/J for Samsung H series at a fraction of the cost (COB LEDs can achieve similar levels).

So compared to T8/T5HO, I can give the same amount of photosynthetic relevant light with 1/2 of electricity cost of T8/T5HO. Some cheap LEDs like those LED strips which you can cut into length aren't any better than T8/T5HO.

You can take a look at the Table 3 of this paper: Economic Analysis of Greenhouse Lighting: Light Emitting Diodes vs. High Intensity Discharge Fixtures
Note that lots of these LEDs in the paper are pretty old.[/URL]

 

Thank you for this info.
I was using completly the wrong type.
I am very sorry for all this.
Sometimes I am such an idiot.

 

I care about the efficiency very much.

LEDs are the best light bulb, I have several plants growing very nicly, I don't know why I said what I said.
The plant that I had trouble had cheap batt. powered LEDs.
I am sorry everybody.

Must be the other personality.

 

Thanks Naoki.
Again, sorry for arguing.

Hope we can be freinds.