Growing Area in the Balcony of Apartment

I think you’re going to be very happy growing on that kind of shelving unit. I have used them myself. In fact, I bought one over the summer, adding a second set of wheels, and made two, 2-shelf units so I can move my plants in and out off the deck and into the kitchen.

Marni is right that you’ll want lights for each shelf, as the plants will block the light penetrating to the lower shelves.

Unfortunately, that LED panel you have is simply not providing enough light, even for the top shelf. Instead of the chips emitting light straight at the plants, they are oriented around the perimeter, “shooting” inward, where they illuminate baffles that scatter the light. While it may look pretty bright to the human eye, the output is quite low. A couple of years ago, one of my wholesale suppliers sent me one like it, and I was excited to try such a thin, clean design, but it just wasn’t appropriate.

Take a look at theorchidhobbyist.com. Jeff Young, the owner, is an orchid grower and he invested some serious money in a PAR meter and spectrophotometer so he could design LED lamps specifically for orchids, and the ones he has made are quite inexpensive, yet the “best bang for the buck” out there. I used to have custom-designed LEDs made for resale, and these are far superior.

 

Hi Iris! Who was it again that said "great minds think alike"?
Here in Holland professional growers occasionally upgrade their greenhouse lighting and dump their old ones in the second hand market. I bought a few Philips greenpower light bars for a song to help my babies through winter. Even with one per shelf it makes quite the difference. They are light in weight, stay cool and are perfectly waterproof. Happy with it.
The LED panel you are using is available in "plant specification" light (purplish) and is used in growing very young plants here from seed to first planting in full soil. Indoor lettuce growers use them a lot. But they are expensive and a full six shelve tower will be a small fortune. But there too, I keep my eyes peeled at the second hand market.

 

As a supplemental light source, it might provide enough light, but it’d still be hesitant to trust that.