Seedling grow lamp advice

vsmfarqp

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Oct 7, 2012
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I am starting a vege garden, and have started some seedlings in soil blocks, but being me, I want to tech it up and make some LED lights to try and get them growing a bit better and more stocky (they only get light through the window at the moment and they are pretty spindly)

I have done some reading and been looking on ebay for supplies, but thought I'd ask some of you LED experts before I buy anything :)

So far I have come up with putting 10 3W LED's onto this heatsink:
http://www.ebay.com/itm/1-pc-Aluminium-Heatsink-8-3W-Aquarium-Led-Bulb-/170643940622

using this power supply: http://www.ebay.com/itm/20w-30w-7-1...177?pt=LH_DefaultDomain_0&hash=item3362a557c9

As for LEDS, I figure from my reading I need a 4:1 Red:Blue ratio, so 8 Red and 2 Blue on the one heatsink. I am trying to do all this in the cheap, so looking at the cheap 3w LED's on ebay.
I'm not sure if one of these heatsinks with the 10 LED would be enough but I might need a couple

So some questions:

-- On ebay they seem to sell the 3W LED's with and without the STAR heatsink eg:
http://www.ebay.com/itm/10-pcs-3W-H...971?pt=LH_DefaultDomain_0&hash=item3379a73f63 vs http://www.ebay.com/itm/10pcs-3W-Re...978?pt=LH_DefaultDomain_0&hash=item1e6e9beb62
I was planning on getting the ones with star heatsink, but could I use the bare ones just glued to the heatsink? If so would it be much harder to do?

-- The blue and red LED's have different forward voltage, can I run both the 2 blue and 8 red ones from that same power supply?

-- If I make multiple heatsinks with LED's is it best to get one of those power supplies per heatsink or one big power supply?

-- does 10 LED on one of those heatsinks / one one of those power supplies seem OK? can I use more / should I use less?

-- In general does this all sound right? These constant current supplies are still confusing me, my mind only works with constant voltage :)


Any advice would be great, thanks!
 
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AnAppleSnail

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There's no need to use disco lights. My aquarium plants do just fine under white (fluorescent or LED) lighting. Red photons don't seem to be missed by seedlings anyway. I started my basil this year under neutral-white LED and it's all about three feet tall now. White lights are prettier and look less like a seed grow op.

Parallel LED strings must have the same forward voltage. Anything in series has the same current supplied. So you could get two drivers (one red and one blue) to control separately, or just mix them (alternate red and blue) to get parallel voltages to work.

Warranty service and consistency are better with a proper supplier. Ledsupply, led-tech, cutter, mouser, etc. Power needed depends on how much dirt you're lighting. Heat sinks size depends on power.
 

vsmfarqp

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Oh yeah white, didn't even think of that. I have some white 12V white LED strips that I have ready to put down my hallway, waiting for some microcontrollers to arrive before I can put them up, so might use them for my seedlings in the meantime.

But I still want to get the disco lights, white LED strips 'aint going to impress anyone :) It's all about the facebook likes haha

So with the constant current driver like the one I linked to, I would just attach one string of LED's in series and it wont matter about differences in forward voltages as long as they can all use the 600ma current?

Also not too worried about warranties etc, all the Chinese eBay stuff is so cheap, and it would probably cost more to return any faulty stuff that it is worth.
 

vsmfarqp

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I spent way too long yesterday wiring up the LED strips I have for the hall, and put them over the seedlings, thought I'd put up some pics. Still keen to hear feedback re my 'disco' light plans above!
http://i.imgur.com/hVsL6.jpg
http://i.imgur.com/Tb7M8.jpg
http://i.imgur.com/agC6K.jpg


Your images are too large and have been replaced with links Please resize and repost.
See Rule #3 If you post an image in your post, please downsize the image to no larger than 800 x 800 pixels. - Thanks Norm
 
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vsmfarqp

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Oct 7, 2012
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Yeah I was wondering about the size those pictures came out, sorry!

Thanks, this is my first time trying a vege garden, its at my nanas house as she is too old to use it properly anymore. I'm doing some lettuce, it has already been planted out in the garden. Yeah those lights are a bit oversized hehe. Plan is to grow the ones I can here, and get them strong before I put them out as I can't get up there to tend to it every day etc. Still, back on topic, any advice on my disco light plans would be great! cheers.
 

vsmfarqp

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I have been thinking, dangerous I know...

With the above power supply + heatsink + star LEDs would be about $30 and produce around 600 lumens, 20 lumens per $.
Then I thought about using some of those 5050 LED strips, it seems hard to find details but it seems they are about 15 lumen per LED, and 300 of them on a 5 meter strip for $15. That's 4500 lumens for $15, 300 lm/$!

I have seen people say lumens don't matter for plant growth, its PAR that matters.

So what do you think about using something like this? http://www.ebay.com/itm/LED-Strip-5...799526?pt=US_Car_Lighting&hash=item2575f54a26 Thanks!
 

Drumwerx

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Oct 12, 2012
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Hey vsmfarqp Did you ever do the LED lights or strips? I like the idea of the strips and wanted to find out how it went becasue I am looking at the same things. I bought soem 3w led from China and will be building about the exact same thing in 3 small panels and then I wanted to try the strips.

Let me know what you did.
 

vsmfarqp

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Oct 7, 2012
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Hey vsmfarqp Did you ever do the LED lights or strips? .

Apart from using the white LED strips I had, I didn't get anywhere else with the idea. Once the seedlings got big enough, I planted them out in the garden. I get distracted very easily, and I moved on to other projects (I'm making a portable boombox now lol :) I havn't even looked at the garden properly for a month!
 
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