My growing rack.

[papayj]

This year, I moved into a new house and the only place I can grow plants was the northern balcony. (sigh) So began my quest for growing under the lights.

This is what I got so far:



My current setup includes:

two 25W T8 LED tubes
one 35W E26 growing LED
one 25W E26 growing LED

Timer set on 06:00 to 20:00

The brightness is around 600 fc (bottom) to 2,000 fc (topside wire rack)

And I plan to add couple more supplementary lights to be really sure. :-)

[Nexogen]

Friend, I guess you rushed using only red and blue. With white LED you can get the same result but much more accessible to the human eye.

[papayj]

Originally Posted by Nexogen

Friend, I guess you rushed using only red and blue. With white LED you can get the same result but much more accessible to the human eye.

Well there ARE white LEDs. (To complement carotenoid spectrum.)
It's only that there are more red and blue LEDs that it appears reddish purple. (The ratio between each colors are about R:B:W = 4:2:1) And the phone's camera makes it more redder than actually is.

Also plant physiology was one of my major in college.... so at least I have some idea of what I am doing now. hehe. Besides, no one is around during the day, and when I do stuff around at the evening or morning I just turn on the main ceiling light.

[Joelovefragrance]

I'm curious what kind of plants you are able to grow that require high light conditions such as vandas and cattleyas

[Nexogen]

My friend, 25 years ago I bought the first orchids from the Jongno (-O- ga) flowers market (I do not know if it still exists). But let's get to the LED. I use COB LED white and just added 660nm, 430nm, etc. I personally built my light, using the exact component with the desired spectrum of plants. The light for human eye is white. Years ago I used only red and blue (the light generated by red and blue LEDs is very disturbing to the human eye) now are white COB with the spectrum close to that needed for photosynthesis.

[Nexogen]

Here's how the spectrum looks at the COB used (4000K) and I add the right things. With max 25W per square foot, blooms any cattleya.

[Nexogen]

Here is the final spectrum approximately.