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Unregistered
07-02-2011, 12:33 PM
Hey guys,
I'm interested in building my own LED based lightning system for in-door hydrophonic growing,
And since I'm looking into building my own lightning system- I have a few question that I hope you guys
could help me with =]

1) Growing area : 2 meter x 2 meter
providing that area, what is the amount of LM I need to achieve in order to grow effectively ?

2) I understood that LED wise, I need 660nm red leds and 450nm blue leds, what is the best
ratio between those two?

3) given I'm going to use, for each of the led types a high-power 1W led, how many in total would I need to get?

Thanks a lot!!

Medicinalcultivation
07-12-2011, 04:38 PM
I don't know where you got your color specs but the optimal color for red is 630. 660 is the next best color of red which isn't too much below 630. I can tell you that if you are running all 660 red LED's without any 630 Red or a Warm White LED, then you are gonna lose a lot of production. The plant can use all the red between 630 and 660 but since its not provided, the plant will have to convert energy to what those spectrums would have provided for the plant. Its easier for the plant to convert this energy when it has more than one optimal source of each color (in this case red). Blue only has one major spike on the color chart for photosynthesis and its 430, not 450. But, I can imagine that you would get the same production out of both colors of blue if your only using 660 red LED''s.

I build custom led lights and I have had to go through a few led providers to get color blends that work well with my specifications. I only use a tri-band color spectrum. I opted to go for 630 red LED's and I get my supplemental light for 660 red from my white leds. I opted for white instead of warm white or cool white because it has all colors of the rainbow. Then obviously I use 430nm blue.

It doesn't seem to matter what type of plant I grow, tomato, bell pepper, beans, every test the plants leaves point as straight up as the new tops would possibly allow during peak ph times!

I have pics and information about my lights design, color spec etc. but I am a new user and have to wait to be able to post links =(

Medicinalcultivation
07-12-2011, 04:48 PM
If your going to use High Power LED's, I would recommend getting 3 watt instead of 1 watt. Unless you build a driver specific to your design, your never gonna get the LED's to run at 1 watt each. With the available resistors in the market, you will get about 70%efficiency per led. If you opt for 3 watt LED's, your only gonna lose the same amount of light per led which -70% is 30% since its 3 times more watts per led you take that 30%and devide it by 3 and your actually only losing 10% light per led. And you get more light out of the same amount of space because 3 watt LED's are the exact same size as 1 watt LED's.

Medicinalcultivation
07-12-2011, 04:59 PM
As far as your grow area. You can't measure the light in lumens because a lumen meter measures the amount of green and yellow light emitted =). LED is measured in PAR value in which you would have to purchase a PAR Meter to measure your light coverage. However, I find that testing by sight works very well with LED's. Since they don't have the heat output as HPS and HID, you can put them closer to the plants utilizing the light shadow provided by the built in reflectors on the individual LED's. To find your light shadow, Just hold your LED Light against the wall, pull it away from the wall until it has the amount of intesity you would like it to have just below the light shadow (approx 3 inches) and the light is in the center of the total distance of your grow room. I can tell you this, if you are planning your yeild on comparable HPS and HID cubic foot information, LED will provide more lush and full plants given the same amount of space. Even if it seems the light isn't penetrating the canopy as much as an HPS or HID. It is better to build smaller lights and spread them out then to try to concentrate all the light in one area on one light.

Garibaldi
07-15-2011, 10:09 AM
I don't know where you got your color specs but the optimal color for red is 630. 660 is the next best color of red which isn't too much below 630. I can tell you that if you are running all 660 red LED's without any 630 Red or a Warm White LED, then you are gonna lose a lot of production. The plant can use all the red between 630 and 660 but since its not provided, the plant will have to convert energy to what those spectrums would have provided for the plant. Its easier for the plant to convert this energy when it has more than one optimal source of each color (in this case red). Blue only has one major spike on the color chart for photosynthesis and its 430, not 450. But, I can imagine that you would get the same production out of both colors of blue if your only using 660 red LED''s. =(

I'm not sure where you got your info either, but chlorophyll a has absorption peaks at 410, 430 and 662 while chlorophyll b has peaks at 453 and 642. Of course, plants generally need other spectra for full healthy growth and flowering/fruiting. The spectra produced by white LED's differ's considerably between manufacturers even though they may call them by the same names (cool, warm, daylight, etc.) There is also a synergistic effect than generally increases absorption activity when 700nm is included. I prefer 5-10W LED's just because they take less time to wire up :cool: