really... good to hear that you're not worried about burning your house down. what is the equivalent wattage, by the way.
I grow my african violets on my window sill, why would I want to use led's on them? my roses grow great under just shop lights, and I've got a CMH lamp growing my tomatoes that works great. I don't think it's a matter of critics or whether they work, but there are other cheaper and better lights out there.
The one and only purpose for LED grow lights is if you wish to grow cannabis plants in a computer case or a small drawer for example, besides that, it's conventional all the way.
Long wave length LED's at 730nm are also useful to stimulate flowering in long night plants, where the required period of darkness is shortened by 4 hours. This also has applications for cannabis, which I use in my own personal grow. Glad to hear about your enthusiasm though, there's nothing nicer to see than an enthusiastic gardener. Sativa.

mrled,
Where did you get your LED grow light at?

canna-gro,

I am glad to see that someone here has a clue about the phytochrome function on long-day and long-night plants. Have you used the 730nm to shorten the dark period of a long-night plant? I hoped to to eventually get to experiment with using 730mn LEDs to see how short a dark period you can successfully get away with. I would like to hear a description of what you were able to accomplish. How short a dark period, how much 730nm light was required, was your dark + light period still a full 24 hours, and did it result in more vigorous growth than normal?

I have known that Pfr changes to Pr at 730nm, and Pr reverts back to Pfr at 660nm. An easy way to get 660nm is to use a Sylvania Gro-Lux Standard lamp(NOT the Wide Spectrum one) which peaks at 660nm at the red end. LEDs are the only convenient way to get 730nm.

As for now, I have no interest in using LEDs for photosynthesis. Currently there are NO industry standards for LED specifications, and the marketing hype in the "plant grow" arena is unbelievably optimistic, if not downright deceptive.

Zink

Hi zink, sorry I didn't see the question. In 1959 Butler et al. discovered the phytochrome flower inducing pigment. In darkness, the reaction Pfr -> Pr occurs, and the Pr promotes flowering in short day plants. Conversely, Pr inhibits flowering in long day plants, and Pfr is the active form in this case.
In total darkness, it requires 4 hours for this conversion to take place; however, just a FLASH of 730nm light during darkness will convert Pfr to Pr, which means that instead of requiring a 12/12 light dark cycle for cannabis for example,
you can use a 16/8 cycle, with a flash of 730nm at the beginning of the dark cycle. For this purpose, I use a home made array of leds mounted on standard electronic perforation board, powered by an ac adapter, of 50 leds, that I purchased from Hong Kong for $100 for a lot of 1000.
They do not normally stock 730nm, but they did a custom run for me on request, I just had to wait a little while.
I expose my cannabis plants to one minute of 730 light. It is just a very faint deep red, but it is enough light to work by. There was a very nice article about it on the internet 4-5 years ago, but I can not currently locate that exact article, in which they talked about mango and other long night plants, but did not specifically mention cannabis. I hold the array in my hand and manually illuminate all of the recesses of my garden, which is just a little 3 x 5' closet grow I built in my cellar. :) Sativa.

Hello, please help.
I have been doing alot of research on LED technology lately and need some help figuring out the viewing angle and light intensity/mcd and how they change in relation to each other.
I want to build my own LED grow light and I want to purchase some LEDs from a manufacturer and they gave me these characteristics:

5mm LED straw or dome type. 20mA.

461.5nm 2750mcd at 62.5 viewing angle 3.07 volt
659nm 1200mcd at 66 viewing angle 2.11 volt
and
623nm 1580mcd at 60.5 viewing angle 2.01 volt

can somebody tell me if these are any good. i've tried to compare but there are so many, i really need some opinions on these. Thanks a lot. Really appreciate it.

If you are looking at a 5 mm LED you looking at a high brightness led and not a Hi-Power led such as those made by Cree and others.

Hi-Brightness leds just don't have any power to do what you want. If you haven't already ready done so, that a look at www.greenpinelane.com where they have tested various led systems and have a number of people building their own.

Working on a little project with about 140W+ of LED. Of course self built or it wouldn't be affordable. Using mixture of Red (630nm), Deep Red (661nm) and Blue 3w each except for the Deep Reds that are 5W.

Just finished my project. 900 T 1/4 leds @ 450 ea. red & blue. 76.5 W total dissapation. This baby throws out some light! Lights up the entire room. Much better than anything on the commercial market!
The light ratio is actual 64% red (630 nm)/36% blue (472 nm)since the reds throw out 8000 mcd each, blues 4600 mcd at 30 deg.

I think LED's are a very good choice for the advanced grower. It takes some time to figure out the wave lengths and how to best utilize them for your plants, but once your winner setup is up and running you get the reward of growing great plants while saving energy costs.

How many of you grow plants to sell, and if so how long will it take for those LED lights to pay for themselves? I use a homemade fluorescent light setup that uses 7 four foot long T8 tubes per a shelf, and they pay for themselves on the first batch of tomato seedlings I grow under them.

I agree LED lights are awesume. I have been using grow lights from Initial-LED since last year and I'm quite happy with the results. No doubt You need to gather knowledge regarding their use for getting optimum results.

My buddy gave me a few DJ Led dance lights ... (Chauvet Slim Par 56 Light source: 108 (36 red, 36 green, 36 blue) 0.25W) Could I possibly grow indoors using these lights?

I have used the same T-8 fluorescent tubes in my 4 foot fluorescent fixtures for the last 4 years and they are still going strong. The cost--less than $40. They say you can get 8 to 10 years from an LED light. @ 5 to 7 hundred dollars for the small LED lights that wouldn't even cover the surface I have now I think I'll pass.

My plants grow strong and healthy under my lights and the cost for electricity is minimal. 1 fluorescent fixture with 2 lights costs as much to run as 1 incandescent bulb. There is not enough heat generated to burn anything even when they are on for 15 hours I can't see the benefit to switching to LED

2 32W florescent tubes draw about 1/2 amp (500ma) at 120V The watts is the current draw not the light output. If you say the leds draw 76w which is 630ma at 120v You also need a power supply, depending on how you hook them up. Not counting the driver loss. 450 red leds at 8000mcd is 3.6million mcd or 770 lumens at 30 degrees the blue is 443 lumens at 30 degrees. Total = 1213 lumens at 30 degrees. The 2 T8 4ft bulbs produce 2800 lumens I would assume across the 4ft. You would need to measure the lumens right under the middle of the Florescent bulb to know the lumens at 30 degrees. Unless my math is off I see the florescent being more efficient and cheaper. I found red 8000mcd leds at $0.59 which is $265 just for the red ones. Perhaps you can find them much cheaper but even at $0.1 that's still $45 just for the red. On the other hand you can buy warm or cool white 50W Light output or 3000 lumins for $18 with driver and free shipping off Ebay, but you also need a heat sink, they get hot. There rated at 140 degree but the output drops off rapidly at 5" to either side of center. I used online calculators for the figures.
A shop florescent fixture and 2 T8 bulbs is less than $15
Please correct me if I'm wrong.

I have a aquaponic system set up in my shed that has no ac or windows, thinking about getting a window ac unit. Ive been doing a lot of looking around for the right light for my setup. i have 4x3 growbed. would like to be able to grow whatever in season. what do you guys think about his led light?

Here is a link that might be useful: led light

I am new to hydroponics and just started a 3x3 ebb and flow and using a Black Dog 450 watt LED. So far I am liking it alot! Ive seen really good reviews on them. The only thing I can say for certain at this point is that LED lights dont have the coverage area of HID type lights. The light I have is about perfect for the 3x3 growing area that I have. Anything outside of that will only get partial spectrums of light due to the directional focus LED's produce.

looks great!
would be cool to get fancy and hook up a solar panel system + battery and have a self-sufficient setup

LED grow lights are really awesome and important for plants to provide proper light by supplying best light quality and brightness to plants.
These are my plants which I kept under Speciality led lighting and plants will easily get right amplitude of light waves necessary for optimum growing conditions.

Isn't it too exaggerated for 400 watt?! I just found 50Watt one, and i wonder it will have the same effect wtih you.