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manders

LED corn bulb

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Anyone tried these? I just replaced a 200W envirolite with a 40W corn bulb, same E40 fitting in the old envirolite reflector. Im getting the same 6000LUX that i got from the envirolite. Ok i know you cant compare directly due to different wavelengths etc.

Has anyone used these for growing plants long term?

I still have one 200W envirolite in use and am really tempted to replace that as well, with easily less than a 1year payback (more like 6 months).

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My understanding is that white fluorescent tubes utilise a mixture of phosphors, which emit at specific wavelengths, to give the impression of white. White LEDs also use a mixture of phosphors for the same purpose. I therefore struggle to see the difference.

 

So, to know for sure you would need to look at the spectral output from the light and see how closely it matches the requirements for photosynthesis - or just see if the plants grow well :wink:

 

Reference: http://www.ruander.com/2009/10/emission-spectrum.html

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I've no experience with plants and these but just fitted the whole house out with the corn led bulbs. The ones I originally bought were "white" but they were very bright and gave the house an office feel, I replaced them for " warm white" which was a much better match for original lighting.

I thought about kitting up a terrarium with the " white" bulbs just as a tester but I don't have the space unfortunately.

The only input I can give is that a couple of " friends" that I know who grow hydroponically are still using the old metal halide lighting or whatever it is...

I paid a little more for my bulbs as they were the dimmable version, I don't know if varying the brightness has any effect on altering the wavelength or just increases/ reduces the wavelength its putting out., just a thought.....

Incredibly impressed with these bulbs though, getting smaller, brighter, cheaper every week....

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Hello, I cultivate some years using white LEDs and they work fine.

Are you sure 200w fluorescent are only 6000 lux? usually a white fluorescent lamp is around 70 lux/watts, therefore 200w correspond on average to 14000lux.

 


Taking as reference the watt, a modern white LED is more efficient than a flurescent lamp of about 30% -35%, wrote an article about AIPC Magazine where I explained the difference.

 

If you use only one shade of white, I suggest the neutral white also called natural white, the color index is around 4500-5000K.

 

Prompt

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Hello Prompt, what plants do you grow with these lights and why you suppose "natural white" is better?

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Hello, I cultivate some years using white LEDs and they work fine.

Are you sure 200w fluorescent are only 6000 lux? usually a white fluorescent lamp is around 70 lux/watts, therefore 200w correspond on average to 14000lux.

Taking as reference the watt, a modern white LED is more efficient than a flurescent lamp of about 30% -35%, wrote an article about AIPC Magazine where I explained the difference.

If you use only one shade of white, I suggest the neutral white also called natural white, the color index is around 4500-5000K.

Prompt

Yes it was only 6000 LUX. Theres a couple of reasons for that, firstly the envirolite is not new and getting toward the end of its life, as we all know flourescent lights deterirorate quite rapidly from new. Secondly the design of the compact flourescents causes significant losses.

BTW what you really mean is 70 Lumens per watt not 70 LUX per watt. LUX is lumens / m2 and is depenedent on how far you are from the light bulb, Lumen output is an absolute number for any bulb.

Im also curious why you went for neutral white, i prefer the warm white myself. Specalist bulbs for plant growth tend to be even lower colour temperature sometimes around 2700K.

Anyway im rather pleased with the corn bulb so far, quite a cheap way to light a tank, 6000LUX should be fine for my ampullarias and a lot cheaper to run than the envirolites and very easy to re-use the same reflector!

Edited by manders

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I messed up, I mean lumens indeed :)

 

The neutral white does best in the blue range compared to warm-white, but less than the range of red, deep red. I think it is a middle ground between the cool and warm tones.
 
I personally use two white simultaneously: neutral-white + warm-white, in some cases, cool white + warm white.
Therefore the warm white for me should never be lacking.
 
Prompt

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X Dave Evans:

 

My experience about the white LED is based on the cultivation of different species, Heliamphora, Nepenthes, Drosera South American and South African.
For about year, I am experiencing sowing under white LEDs and are born from seed successfully: Roridula gorgonias, highland nepenthes, Drosera ultramafica , Drosera regia, Drosera chrysolepis.
 
If using a single shade of white led, I believe that the neutral white is the one with the best range for the wavelengths that can receive and convert photosynthesis plants.
 
I personally, if I can, I build the lamps with two types of white, this allows for the maximum spectrum for plants using only white LEDs.
 
Prompt

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After a couple of weeks i can say the growth is looking quite good, with some nep leaves getting a nice reddish colour. The bulb is really very bright. Looks a lot nicer than those red/blue LEDs and so far i would say the growth is better watt for watt!

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