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Yes

6 (40%)

Yes, but only as supplemental lighting

2 (13.3%)

No

0 (0%)

I have considered using LED lighting, but haven't yet for whatever reason

7 (46.7%)

I have not considered using LED lighting

0 (0%)

Total Members Voted: 15

[TBM]

Hey all!


I've spent quite a lot of time browsing the internet over the past week or so trying to find good LED lighting; now that I've moved I have enough space to actually grow a decent indoor garden, the area I have designated for my garden has only one SWbW facing window (which isn't enough for my cacti), so I'd like to use as little electricity as needed. Right now I'm using a single 2' T5 and a compact fluorescent grow bulb, but that isn't enough light anymore. I've been debating over getting a 3-4' T5 set up but LED lighting would be less electricity, and if built well, it should last much longer. Reviews are hit or miss for most bulb style LED that fit into a standard light socket, and the ones that are round or square framed and have fairly good reviews and have their own cord are kinda pricey... I've also been considering building my own light from the tek that someone posted here on STS, but it's been a while since I've last attempted to do any wiring, and I wouldn't want to mess up and waste good parts

Something's telling me I'm not the only one who's been stalling on trying out LED lighting... maybe this poll will help somehow

[happyconcacti]

I've looked into them as well.

At the rate LED technology is improving, I might start seriously looking at them in 5 years or so.

Also, the main draw to LED grow lights is being able to change the frequencies of light to induce flowering. As far as cacti go, that's not really an issue if you're just getting em through the winter.

Heck, for that matter, MS Smith keeps his cacti in the dark, somewhat cold, and completely dry for the winter to prevent etiolation.

As far as cost comparison goes:
If you bought the Sun Blaze T5-HO (fluorescent) 4' x8 bulb fixture (fluorescent, 54W per bulb or 432W total, $220), ran it for 16 hours per day, for 6 months and your cost of electricity is about 12cents per kilowatt-hour:

432W x 16 hours x 180 days / 1000 (to convert to kilowatts) x 0.12 $/kilowatt-hour =$149.30 per winter

A comparable full-spectrum LED light ($649) runs at 240W.
240W x 16 hours x 180 days / 1000 (to convert to kilowatts) x 0.12 $/kilowatt-hour =$82.96 per winter

Setting these up as simultaneous equations:
y1 = 149.3(x) + 220
y2 = 82.96(x) + 649

Solving for x (the number of winters):
x = 6.5 winters

Therefore, the fluorescent light fixture would be cheaper for 6.5 winters. Past that length of time, it would be a better deal to get the LED lights.


Hcc

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[Mandrake]

Hcc - thanks for a very informative and thoughtful answer.

One observation about LEDs from personal experience. In the case of LEDs, the potency in Watts for the whole fixture may not be a reliable measure of actual output/efficiency, even considering color temperature and spectrum.

The reason is the potency of individual LEDs is very relevant. Generally, the higher the single LED potency, the better the performance; so for instance one 3W LED is more efficient than, say, 12 LEDs of 0,25W each.

Expensive LED fixtures use good high potency LEDs. As semiconductor technology improves and LED usage expands, these become cheaper. But currently, gardeners may be deceived by LED fixtures offered in eBay for low prices and high overall Watt count. Check also the potency of individual LEDs; a high potency LED fixture with 200W total output can be much more efficient than another 200W LED fixture selling at a third of the price. Cheap LED lighting is generally not a good investment, no matter the total of Watts.

Kind regards,

Mandrake

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[SoulGrower]

I haven't personally used LEDs for plants.. however, I have had quite a bit of exposure to many different lighting types bc I used to maintain reef tanks for a living.  Coral require similar lighting requirements as plants (really only differing only in intensity and to a much lesser extent spectrum).  For those that don't know, coral have a symbiotic relationship with zooxanthellae, a photosynthetic algae that live within many coral's tissues.

All good advice here but I think the best is from HCC.  Give it another 5 years.  Mandrake also hit the nail on the head.. don't even consider fixtures with 1W (or less.. YIKES!) LEDs.  The only ones that will truly perform well will be fixtures with >3W LEDs.

My experience was to witness the LED craze with aquariums.  A lot of marketing BS to sort through.  Watched a lot of people convert and then go back to MH.  Fact is, you can't beat a MH.  Period.  T5s aren't bad but you have to replace the bulbs more frequently.  Every 6 months for aquariums (opposed to 12-18 months for MH).  Problem is that over time the bulbs shift out of the preferred spectrum..  I'm not sure how this correlates to plants but assume it would be similar.

In the end, LEDs will really not save you electricity anyhow (right now, when it comes to growing plants or coral).  Actually nor will T5s.  To get the same true light intensity (lumens/PAR).. there is little difference in efficiency between leds, fluoros and HIDs.  The real differences right now more about spectral efficiency and 'coverage'

The advantages of LED fixtures right now, imho, is that they don't generate much heat and that you don't have to replace the bulbs.  They are highly efficient spectrally which is either a good thing (targeting chlorophyll peaks) or a bad thing (not providing spectrum that is otherwise important.. ie for vitamin production and/or other non-photosynthetic processes).  They are also highly focussed (which is why they seem so bright per watt) which requires high densities and/or lenses to diffuse the energy.

Right now, you simply won't beat a good Metal Halide when it comes to performance and even coverage/watt.  I like T5s though as a good compromise for the amount of heat produced.. 

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[TBM]

Thanks everyone for the input!


It's that sort of equation that really shows what I was looking for HCC, +1 on that

The reason is the potency of individual LEDs is very relevant. Generally, the higher the single LED potency, the better the performance; so for instance one 3W LED is more efficient than, say, 12 LEDs of 0,25W each.

I had noticed that there were two different varieties of LED fixtures too (ones with many low watt, and ones with fewer high watt); I had thought that the fixtures with the fewer, yet higher watt LED were the preferred, but I wasn't really sure  

The advantages of LED fixtures right now, imho, is that they don't generate much heat and that you don't have to replace the bulbs.  They are highly efficient spectrally which is either a good thing (targeting chlorophyll peaks) or a bad thing (not providing spectrum that is otherwise important.. ie for vitamin production and/or other non-photosynthetic processes).  They are also highly focussed (which is why they seem so bright per watt) which requires high densities and/or lenses to diffuse the energy.
Right now, you simply won't beat a good Metal Halide when it comes to performance and even coverage/watt.  I like T5s though as a good compromise for the amount of heat produced.. 

I thought metal halide lights were the best for output, but you're right it's the amount of heat produced that's keeping me from wanting to invest in a set up with those lights.

I'm going to leave the poll up indefinitely for now... maybe as time goes by and technology improves people will want to change their vote  

[BubbleCat]

I think I already made obvious I'm trying to go down the same road OP wants to go here, my findings so far:

You can not accurately compare LED and mixed-wavelength light-sources by lumen or lux, plants appear green to the human eye for reason, most sunlight (mixed wavelengths) that reaches a plant can be considered pretty much wasted in terms of photosynthesis. Wikipedia on grow lights has nice basic info on this, also looking at commercial LED grow lights reveals the wavelengths used. So when a "white" or "mixed" lamp produces x lux, a part of x isnt put into any use by the plants, so a LED lamp producing x lux can mean more light for the plant in question (and higher efficiency - a LEDs eff. is roughly estimated to be 0.8, 80% of the energy are put out as heat but this is a big improvement over many lamps).

The spectrum will either need excessive knowledge to get everything right - amd then you might need to find exotic wavelength LEDs than can run into 3 digit $ if youre unlucky, or it will simply limit the applications of LED to supplementing in low light conditions (making sure you still get as much as possible).

The lifespan of a LED can (!) be enormous compared to edisons invention, but edisons invention works its lifespan at very elevated temperatures (and also needs those to operate) while a LED loves to be kept cold (in range of the datasheets spec - or simply at room temperature) from any given operating temperature and its associated lifespan a 10 K temperature increase will roughly reduce the lifespan to 50% up to a point close at 200 C where a LED will do its job a few minutes. Consider its mass and its power rating x 0.8 amd you'll see it can easily self destruct if not supplied cooling. Cooling will mean bulky passive means or noisy fluid motion cooling.

Yep, LEDs can much more easily be adjusted to trigger certain behaviour in some plants, basically if you have no LED your light will - obviously - appear "black" if you had LEDs covering all wavelengths the resulting mix of light will appear white. From here you could switch off all LEDs your plant doesnt use at all, and following to that you could delete LEDs that trigger flowering when you want foilage and vice versa... And so on - of course this procedure is hypothetical and for educational purpose

The lesser heat generation of LEDs will make plants sweat less resulting in them drawing less water and as a consequence they'll need less watering. Put that into consideration.

If you like thinkering buy bulk LEDs and a massive power source, do your math and design work and give it a try, in all other cases sticking to a commercial available product would be desirable especially at the point where you had concerns about insurance and such - I dont guess someone wants to keep his lamp observed all day, but I do believe in case of a fire set with a homebrew lamp one could find one self in big trouble.

I think the fact that LEDs can run at way lower Voltage than conventional lamps makes them very interesting for DIY, but I consider the whole thing as playing around - some like ^^


I hope theese points, its what I gathered as of yet, feeds your consideration

1 Like TBM likes this.

[SoulGrower]

You can not accurately compare LED and mixed-wavelength light-sources by lumen or lux

Absolutely!  The typical way of evaluating light quality for plants/corals is by using a PAR meter (Photosynthetically Available Radiation).  But a PAR meter won't really work for an LED.  I forget why.. might be bc LEDs are narrow band??  We used PAR meters and got very mixed results when testing LED fixtures.  LEDs in general produced mixed results in the field.

BTW.. If anyone was to go the LED route, I would highly recommend fixtures with CREE bulbs.  They are one of the few that reliably produce components to published spec.. which is important when you are targeting spectral peaks (wavelengths that activate chlorophyll A/B).  Also CREE does the R&D specifically for plant/aquarium specific LEDs.  The last thing you want is to buy cheapo ebay leds that likely won't be at the right wavelengths and/or outputs.

I think in 5 years or so, we may have LED fixtures that approach the performance of MH with an energy savings (and def on bulb replacement!).  I pesonally just don't think we're they're yet. 

I also really think that we may underestimate the need for non-photosynthetic portions of the spectrum, especially for long term health.  I believe it is one of the reasons that MH are tough to beat.  Because it produces a wide band portion of visible and UV light spectrum.  Right now, most LED fixtures target specific chlorophyll peaks.  Although you do see some commercial fixtures now mixing in white ("full spectrum") leds.

You can never beat the SUN    Google "solar tubes"   That would be the best indoor lighting.. and free to run!  If you live somewhere that you can install one..

1 Like happyconcacti likes this.

[BubbleCat]

You can never beat the SUN    Google "solar tubes"   That would be the best indoor lighting.. and free to run!  If you live somewhere that you can install one..

would be no big deal when I look at them, but on one side we are concerning lightning also fpr those cases where the sun wouldnt provide enough anyway so the system might not help growing plants that are used to lots of sun during lets say polar night as a extreme and as far I understand no material has yet been developed that is translucent to all wavelengths (as much as to others) so you might again end up missing some of th suns spectrum wich plants adapted to all time. so yeah - nothinh beats putting a plant outside except when you dont have space or its freezing, hot or dark ^^

I should speed up my developement of a cooling system to be able to provide hands on experience

[23]

cooling system?
[/quote]
 "solar tubes"   That would be the best indoor lighting.. and free to run!  If you live somewhere that you can install one..
[/quote]
cool! > 

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[Chicsa]

Thats a really cool system 23! I studied this in school, you can also do fiber optical cables through the tube and make interesting lighting fixtures too!
http://www.your-solar-energy-home.com/solar-fiber-optic.html

[23]

Wow thats amazing! You should open a topic for that!
I wonder if they include the very FULL light spectrum. I mean they say it does but i wonder...

[BubbleCat]

Cooling system, exactly 23. Day / Sunlight is very intensive compared to usual domestic lightning. So a 60 Watt Lightbulp a room wont do for plants. So I need lots of lux and those can only be produced with lots of power, even tho LED Lights tend to be more efficient, 80 % of the energy one puts in will leave the device as heat. So every Watt LED ( or 200 mW light) generates 800mW in heat and this must be dissipated - or the LED is going to die pretty soon.

[23]

right right

[happyconcacti]

Wow thats amazing! You should open a topic for that!
I wonder if they include the very FULL light spectrum. I mean they say it does but i wonder...

Fiber optic lines are used in spectrometer devices. So yes and no, they capture most frequencies of light. You just have to have the correct fiber optic line that's matched to the Frequencies you desire to measure and/or transmit. For example you have to have a special fiber optic cable to measure frequencies at opposite ends past the visible spectrum (i.e. infared vs. UV).

Spectrometers are awesome. If I had one of these bad boys I could do soooo much testing for LEDs, flourous, MH, ect. frequencies and amplitudes. The problem is that even the cheap ones for only visible light are still in the $1,000 range and the good ones are about $15,000. One expensive toy.

Because it produces a wide band portion of visible and UV light spectrum.  Right now, most LED fixtures target specific chlorophyll peaks.  Although you do see some commercial fixtures now mixing in white ("full spectrum") leds.

The thing with "white" LED's is that they're really blue LED's with a yellow phosphor coating. The main peak is around 450nm which is a blue and it mixes with the phosphorescence of the yellow phosphor to create a smaller but broader peak around 550nm.  This definitely broadens the frequency range to make a "white" light but it definitely falls short of being true white light.  So as far as replicating the sun, no, no.

Hcc

1 Like BubbleCat likes this.

[BubbleCat]

I always wondered how white leds work, I was reasoning if they put a set of semiconductors in there

I think the Solar tubes mentioned really wont do the job, as happy and I stated you will get distorted light wicj is not true to the suns spectrum because as long the device is sealed at one end and the material is one of the commonly known translucent materials the device will absorb some wavelengths more than others wich leaves you with light as good as light thats from other sourced with comparable spectrum.

The main point tho, is that if you look at the device it becomes obvious that it uses sunlight that hits a surfsce that equals its surface area at the roof, channels it down where you can expect some losses (more or less for each wavelength see above) and the lower part of the device is designet to give a great angle of irradiation. So basically sunlight that resches say .5 sqm will be used to flood the whole room, perfectly fine for humans to live in but not enough gor plants, the only way to change this would be make the roof one big translucent surface and the room below is a giant hot house that still doesnt get sinlight spectrum. Even if someone hypothetically went that far it wouldnt be of any help if he lives in an area at a time where sunlight is low and days are short. If the later wouldnt be the case a garden would be a much more sensible choice

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