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LED grow light users


I'd like to add more lighting to my indoor HL chamber as of right know I have a 4 tube T5HO fixture. It does its job but I'm interested in supplementing with some LED grow lights. What are you guys using and what brands and models do you recommend? I'd like to stick to the high quality stuff so I'm not have to repurchase later on so to shoddy manufacturing. the area I'm looking to light is 36" tall 48" wide and 36" deep.

Looking forward to your replies,
I strongly recommend building your own system. Cree has some really nice solderless XMLs. With a custom set-up you could always add more/less lights to your heatsink or later buy a different heat sink as well. rapidled has some good products. Check them out.
As raisetup01 said, if DIY is a possibility (very easy), you get the best bang for the money. COB based ones are even easier than smaller ones like XML2. Bridgelux Vero 18 and 29 4000K is something I would go (for the initial price and high efficiency). But Cree CXB3070 is great, too (a bit more pricey). 3-4 units of Vero 29 or CXB3070 driven at 50W each will cover the area well (each unit will be around $60-70). Here is a link to how-to which I wrote (it uses an older CXA3070, message #16):

I recently found an affordable T8 LED, which can do >140 lumen/watt, by browsing DoE Lighting Facts database. This could be a game changer.

If you want pre-build one, an independent test has shown high PAR efficiency of Build My Led units (I have no association with them, and I'm not sure if I'm allowed to put a link here). There are lots of bogus marketing with the so-called LED grow light, so be careful.
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BUILD YOUR OWN. Get high quality LED lights and a driver and heatsinks. I don't trust those red/blue led "grow lights" sold on ebay and amazon anymore. I've bought a couple of those then built my own with components from RapidLED with EXCELLENT results.
Let's pretend, just for a second, I am a fairly handy person who can follow a walkthrough, but have never built an LED system before, what exactly should I be looking for in the LEDs/components. Also, is there a decent walkthrough anywhere for building it from steps A-Z?
Some of the solderless kits are very nice. I ordered one from them about a year ago and have had great results. There are also some great threads on here about light quality and wavelengths. It shouldn't be too hard to figure out once you take a look. Also, RapidLED allows you to customize your light selection, so in some of the kits if you specify in the order that you want certain wavelength lights, they can substitute them out. I recommend them highly
yep its super easy with the solderless LEDs. You dont even have to drill holes in the heat sink to attach them. you can use glue that they sell but it will be permanent.

i got the this kit: http://www.rapidled.com/12-led-plug-n-play-retrofit-kit/

I ordered 12 xml2 leds and this heat sink- http://www.rapidled.com/6-x-12-premium-heat-sink-and-enclosure/

Im sure there's a "walk-through" somewhere on the internet but it's pretty self explanatory when you just need to buy a kit

i made a topic about my light: http://www.terraforums.com/forums/s...results-from-my-CREE-XM-L2-LED-grow-light-kit

I say it's tedious putting the screws in that particular fixture but i have pretty large hands and those screws are tiny. I got about three done before i asked my girlfriend to take over. she had no problem really..

if i were to do it again with that same kit and fixture i wouldnt have gotten the dimmable version. Since it has a fan, i can run it on high and it never gets hot. I don't use the dimmer but i guess its a neat feature anyways...
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VBkit, if you want to go with a COB option (a bit newer technology), here is what you need (links to good place to buy are given).

Vero 29 $29.37
Cheap (but pretty efficient) 50W (1.4A) LED driver $11.75
CPU heatink $12.99
Thermal paste (here is a link to an example)

5-12V AC-DC adapter (wall wart).
Some 18 gauge wires (I use door bell wires from Lowes).
AC outlet plug/wire
short M3 screws

1. The trickiest part is drilling holes to the heatsink, and tapping. It is easier with drill press. Use oil to lubricate during the drilling, and don't push too hard.
2. connect DC side of the drivers to LED with 18gauge wires (+ goes to +, and - goes to -)
3. connect AC plug to the AC side of the drivers.
4. Apply very THIN thermal paste to the LED, and attach it to the CPU heatsink. (note if you are soldering wires to the LED, you should solder BEFORE attaching it to the CPU heatsink).
5. Connect AC/DC adapter to the fan.


LED Driver: This setup gives about 50W. You can use higher or lower current (watt) drivers. If you drive at a higher current, you get more light, but the efficiency goes down slightly. 1.4A driver is economical (pretty good initial price and overall efficiency is very high). There are better drivers like Meanwell, which can do a couple percent higher efficiency. But the 1.4A driver I linked has 89-90% efficiency from my test (instead of 92% or so of Meanwell). Vero 29 can be easily driven at 100W level.

This setup gives 2320 footcandles and 309 micro mol/m^2/S of PPFD at 1 foot (58.2W of measured energy consumption). But mine is 2014 version of Vero 29, and the 2015 version gives quite a bit better performance than mine.

For orchids (which requires less light than CP), I use 4 units to cover 16 sqft (4x4'). The light source is about 3-3.5' above the bench.

AC/DC apapter for the CPU fan: I just find some cellphone charger or whatever from trash transfer station. 5V or so is enough, and keep the fan quiet.

Heatsink: I gave a link to the one which is pretty good, but I usually find a heatsink from old computers (e.g. trash day).

Solder vs solderless: This can be done solderless if you don't like to solder. Then you need this:
Molex Pico-Ezmate harness to connect wires to the LED
Wago 222-412 to connect wires to wires.

Pico-EzMate seems to work, but it seems a bit flimsy. So I would go with direct soldering.

This kind of setup is frequently used by MJ (and some orchid) growers.

The link to the orchid site which I provided in the previous message has a bit more info.

COB is easier to get lots of light than individual LEDs like XML2. Efficiency depends on the driving current, but COB efficiency (since we usually drive it softly) is similar to XML2, but initial cost is lower with COB. One disadvantage of COB is that it is a point source. So a panel with many individual LEDs spread in a wider area gives a bit more homogeneous light, and it creates less shadow (i.e. advantage of diffused light).
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  • #10
I'm currently using a Jungledawn LED bulb. It's a one directional rotating strip that screws into a standard E-27 bulb fixture, and it has been GREAT for my plants. The Akai Ryu VFTs I have growing directly underneath it are pure maroon, and the sundews are all nicely colored as well. Can't remember how much it cost me, but I'll tell you it was DEFINITELY worth it.

Now, though, I'm looking for an LED bulb that provides enough light and fits in a standard desk lamp. Any thoughts? This is for a mini-bog.
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  • #11
I'm currently using a Jungledawn LED bulb. It's a one directional rotating strip that screws into a standard E-27 bulb fixture, and it has been GREAT for my plants. The Akai Ryu VFTs I have growing directly underneath it are pure maroon, and the sundews are all nicely colored as well. Can't remember how much it cost me, but I'll tell you it was DEFINITELY worth it.

Now, though, I'm looking for an LED bulb that provides enough light and fits in a standard desk lamp. Any thoughts? This is for a mini-bog.

Most screw-in type LED bulbs aren't so efficient yet. But Philips GreenPower has one which has a very high PAR efficiency:
Horticulture Products - Philips Lighting
  • #12
Went to Walmart and found a GE bulb that replaces a 60-watt, color temperature at 5000k and throws 1000 lumens. Best I could find there, haha. Checking out the philips stuff now, though.
  • #13
Saw LED, and immediately thought of Vraev's awesome terrariums. He uses Radions.
  • #14
Saw LED, and immediately thought of Vraev's awesome terrariums. He uses Radions.

... At 300 bucks, that's really a steal, right? That's more than a month of rent for me, lol! Ah, I love how 2 of my hobbies are really quite cost-prohibitive if you want to put together a display that's more than mediocre. I mean, I imagine I could put together a setup of LEDs similar to this for a fraction of the price, without all the fancy automated systems, but that takes more knowledge than I have, plus I have no clue where to even BEGIN looking for LEDs in the UV spectrum :p
  • #15
Near-UV LEDS are available at least on ebay, called "royal blue" and "deep red". I use them in my LED fixtures for CPs and they work great.
  • #16
Why are you using (or interested in) UV for CP? I'm curious whether there is a scientific evidence showing UV is good for CP growing (I know a little bit about UV on crop plants)? You aren't going to eat or smoke them, are you? :poke:

Usually "deep red" (or "hyper red") LEDs are around 670-680nm, there are some goes beyond 700nm (far red, which is relevant for phytochrome). This isn't UV, though, UV is below < 400nm. Real UV LEDs (I think UV-A to UV-C) do exist (I don't know the details), but it was very expensive.
UV LEDs ramp up the quiet side of the LED market (MAGAZINE) - LEDs
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  • #17
UV is 320(uva)-370(uvb) nm

When one is trying to replicate the sun using leds SMALL amounts of UV light are all that is necessary, yet still necessary to say you are replicating the Sun. Another thing one has to take into consideration is the spectrum of the Sun changes throughout the year.

Looking at the peak PAR and response of pigments we have 4 types of main pigments we need to activate.
Chlorophyll A
Chlorophyll B

They each correspond to certain spectrums of light and respond accordingly to more or less of that spectrum of light.

The most responsive parts of the spectrum for chlorophyll A are 480nm and 510nm, pigment response is equal for both spectrums.

The most responsive part of the spectrum for chlorophyll B is actually 440nm (80% responsive ) and 620-640nm (20% responsive)

The most responsive part of the spectrum for B-carotene is 505nm , and a small spike <10% at 560nm

The most responsive parts of the spectrum for xanthophyll are 400nm , 465nm , 515nm and 660nm all equally make xanthophyll respond.

To "mimic" the Sun and use a spectrum that is comparable to the total year round spectrum of the , one would need an led for every type of chlorophyll wanted the plant to produce. A "full" spectrum led light should include 1 near UV led (370-400nm) , 1 blue at ~510nm , and 1 red at ~640

This is because the biggest spike for b-carotene is at 505 and the 510 should be pretty helpful with that. If not a green led at 560 would guarantee that pigment being present. Under the leds it would look strange and colourful, but under normal light your plants will look vibrant and the colours of the plants themselves the reds and the greens will be very lush looking. You don't need more light in these spectrums, lots of light from your t5ho lights supplemented with smaller full spectrum led systems will make some for very fast growing plants. I personally plan to do this myself that's why I've done the research on it.
  • #18
WOW! Thanks for sharing that info! Now that I know where to find it, I might consider putting together my own full-spectrum supplemental light panels for my plants. It's gems like this little post that make me want to stay involved in hobby forums.
  • #19
No problem that's why I broke out my note book, feel free to double check any of my work. I have a friend building me a full spectrum led light to add the right spectrum into my light spread, my main light source is sunblaster t5ho lights right now but I still want to see first hand what this spectrum can do. I plan to do a side by side comparison between the full spectrum led lighting and just normal 6400k cool white fluorescent light bulbs
  • #20
It is good to know the "absorption" spectra of accessory pigments on the antenna complex of the photosystems. But to me, the action spectrum of photosynthesis is more relevant. This is because in addition to the absorption, you'll need to know the ratio of the pigments and efficiency of the energy transfer from the accessory pigments to the reaction center (only the energy transferred to the reaction center P680 and P700 is relevant for the photosynthesis). So the action spectrum is more integrative efficiency of photons at different wavelength on photosynthesis (instead of just absorption). From this, one would conclude that using all red photons is most efficient. But there are issues with photomorphogenesis (e.g. you need to consider the effects of phytochrome, cryptochrome etc), so pure red doesn't do so well for most plants. In addition, there are interaction among wavelengths. The absorption and action spectra are measured under monochromatic light. So if you use more than one wave length, the photosynthetic output may not be the sum of the wave lengths. An example is that green light becomes effective once you start to saturate the plant with red light (this is fairly recent discovery).

I'm sure that eventually people would make progress toward optimal grow light spectra (different for different species or different life cycle stages), but all I'm saying is that knowing the peaks of the absorption spectra is a good start, but it is just a part of it. Sorry for lecturing this, eithan, if you have know these issues already, but others who are not familiar with Plant physiology may start to think that the absorption spectra is the only important thing. In reality, it is much more complex (but this doesn't mean that hobbyists shouldn't experiment).

Also, I'm pretty sure that imitating the spectra of the sun is not the goal. Remember the light environment where the precursor to the chloroplast evolved? It is different from the sun on the land.

This may be an easy and interesting read for people interested in the topic: