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White LED experiment

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I've been keeping my eye on white LED developments for some time, with the ultimate goal of being able to grow plants under them. Philips produce a 7W 4200K GU10 white LED lamp which looks quite promising, so I bought one. The specifications can be found HERE. For the experiment I am going to try to grow a Heliamphora pulchella (Akopan) under one of these lamps. The lamp has a 40 deg beam angle and is placed approximately 5cm above the top of the tallest pitcher. The beam is cool, hence being able to put it this close to the plant. Whilst 7W does not sound like very much, the beam is very directional so the majority of the light is focused on the plant, unlike fluorescent lamps which scatter light in all directions and are virtually impossible to focus.

This is the initial setup on 30th August 2010:

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By 5th September 2010 changes in colouration are already apparent:

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Mr Mobile,

Please can you tell me where you obtained the device and how much did it cost ?

I guess you are driving it with a homebrew constant current generator ?

I bought my brother two Cree 5 Watt LED's for Christmas for his bicycle. He thinks they are they are great. They were about £10 each and included a 10 degree lens. The same ebay source ( led-dna ) now includes lenses of varying angles. All you would need would be a 6 to 24 volt supply capable of supplying the necessary current for the number of devices you choose to use.

I am always interested to hear of your experiments.

Roger

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Mr Mobile :whistling:

This is a GU10 LED lamp that simple fits into a standard GU10 light fitting, in this case it's a desklamp purchased from Argos.

Carl

Edited by mobile

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...white LED...

Nice experiment - and you are no longer absolutely convinced about "optimized wavelenghts" with monochromatic light when it comes to LED lighting?

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Nice experiment - and you are no longer absolutely convinced about "optimized wavelenghts" with monochromatic light when it comes to LED lighting?

No, I still believe that using monochromatic wavelengths that plants can utilise is the most efficient lighting, as per NASA experiments. If you look at the spectral distribution for this lamp you will see there is a large peak in the green which will be of little use to the plant. Ideally the lamp would have the blue peak of the CW (4200K) and the red peak of the WW (2700K). However, this lamp has a very bright output and is very directional so hopefully there will be sufficient quantities of plant useful wavelengths. In addition, I want to use this lamp in my living room and a red/blue LED array would not look very aesthetically pleasing.

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Good looking plant. Maybe this is the way to go for growing helis indoors without the trouble of a terrarium. May be a good solution for over wintering.

Would more lamps be needed for a greater number of plants?

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Good looking plant. Maybe this is the way to go for growing helis indoors without the trouble of a terrarium. May be a good solution for over wintering.

Would more lamps be needed for a greater number of plants?

I think that to grow several plants you would need an array of these and that would get prohibitive expensive. These lamps are still quite expensive but I would imagine that the price will go down as they become more commonplace. It's a nice setup for a feature plant.

I'm not sure if this would negate the need for a terrarium either in all cases. The plant I have came from a grower who grew it in an open top tank, so it's used to lower humidities.

Edited by mobile

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I'm going to try this-http://cgi.ebay.co.uk/LED-grow-Light-hydroponic-weed-hash-growing-lamp-bulb-/200468262789?pt=UK_HomeGarden_Garden_PlantsSeedsBulbs_JN&hash=item2eacd6ef85

Though not for growing Hash, I'm gonna set up a windowsill tank for my Nepenthes Hamata ,if it goes well ,I hope to grow a heliamphora in there.What do you think?

Edited by petesredtraps

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I'm going to try ... ebay.co.uk ... What do you think?

Did you read the

Manufacturer Specifications

* Main Function: LED Grow Light

* Power Output: 50W

* Input Current: 0.46A/0.23A

* Input Voltage/Frequency: 110V-220V, 50/60Hz

* Lumens: 400-450

* Input Current: 30mA Maximum

* Input Power Consumption: 6.5W

???

Much more "Power Output" than "Input Power Consumption"?

And what about "Input Current"? Once there is a 0.46/0.23A rating (should be for 110V and 220V), but some lines later the rating is "30mA Maximum", that is 0.03A.

So all specifications are subject to a change by the factor of about 8 while you read them?

If I should make a guess, then this lamp has a power consumption of 6.5 Watt and it makes (manufacturer rated) as much light for growing plants as a 50 Watt incandescent bulb. An incandescent bulb @50 Watt would use Input Current of 0.46A/0.23A (@110/220V), but this bulb only uses Input Current: 30mA Maximum. I don't know what else should be the meaning of the contrasting specifications.

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Did you read the

Manufacturer Specifications

* Main Function: LED Grow Light

* Power Output: 50W

* Input Current: 0.46A/0.23A

* Input Voltage/Frequency: 110V-220V, 50/60Hz

* Lumens: 400-450

* Input Current: 30mA Maximum

* Input Power Consumption: 6.5W

6.5W input, 50W output... they generate power... wow! I wonder if the worlds physicist know of this phenomenon... it could potentially solve our future energy needs if we can efficiently convert it back! :sun_bespectacled:

Joking aside, I think it is supposed to be 'equivalent' light output but even this doesn't make much sense as a typical MR16 halogen lamp will give out a conservative 15 lm/W so that'd be 750 lm for a 50W output, but this lamp is giving out 400-450 lm.

Edited by mobile

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mobile, i'm liking the look of your setup, can you link me to the lamp on argos' site (i like the look of that lamp) so i can go buy one and stick a Heli under it! I simply dont have the space or time for complex lighting and terraria so this would be perfect to try.

-edit: dont worry, i didnt realise that industrial look was the bulb itself!

Andy

Edited by naryn

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mobile, i'm liking the look of your setup, can you link me to the lamp on argos' site (i like the look of that lamp) so i can go buy one and stick a Heli under it! I simply dont have the space or time for complex lighting and terraria so this would be perfect to try.

-edit: dont worry, i didnt realise that industrial look was the bulb itself!

Andy

If your interested in the led / bulbs try your local Wilkinsons as they had some in my local the other day though they start at around £4 and up

but they have about 4 or 5 different wattage's and most claim to be in the 2700k range with one "daylight" so around 5000k-6500k

could be worth a try with one of each? best of red and blue spectrums.

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If your interested in the led / bulbs try your local Wilkinsons as they had some in my local the other day though they start at around £4 and up

but they have about 4 or 5 different wattage's and most claim to be in the 2700k range with one "daylight" so around 5000k-6500k

could be worth a try with one of each? best of red and blue spectrums.

At those prices they are extremely unlikely to have sufficient light output for plant growth. The Philips one pictured above is 7W and costs approx £25.

Edited by mobile

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At those prices they are extremely unlikely to have sufficient light output for plant growth. The Philips one pictured above is 7W and costs approx £25.

I think they were 3w, 5w, 7w & 9watts @ approx £4 upto around £30.

Ill take a look when im in there next but think there were 2 different brands there, the philips and another type.

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Where did you get that plastic tub from? Hope you don't mind me asking.

For the tubs try your local Pound shop, i got some very similar to those that were sold as microwave food tubs with lids.

I think mine came from poundland for 10 tubs / lids.

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Morrisons Supermarket sell ready meals in similar tubs. They are 800ml, about the diameter of a CD and about 10cm high. The label peels off easily without leaving a sticky deposit.

Edited by Peabody

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Has anybody tried the 2ft T8 led light replacements for fluorescent tubes? They seem to be getting cheaper and offer a similar amount if light as the fluorescent for half the power consumption. Haven't tried it myself yet but they look interesting.

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Where did you get that plastic tub from? Hope you don't mind me asking.
Morrisons Supermarket sell ready meals in similar tubs. They are 800ml, about the diameter of a CD and about 10cm high. The label peels off easily without leaving a sticky deposit.

Yes, that's where I get them from :thumbsup:

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Sunday is feeding day (with tomatoes plant food of course!), so I took the opportunity to take a picture of the plant. As you can see, it is putting out new pitchers...

17102010405.jpg

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Growth and colouration looks great (sphagnum seems to be loving it also). Just imagine what could be done with an array of these. Their compact, low power and lasts a lifetime (now just the long haul to add cheap to the list).

Your only pitcher feeding right?

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Your only pitcher feeding right?

No... I root and pitcher feed.

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