My set up is shelves with ordinary two fluorescent lights.
I stack books under the trays to raise or lower the trays so they are close to the lights. I can fit two trays under each so 6 trays. I have another fixture over a desk where I prop the trays on boxes so they are close to the light.
One set up,--- I saw at Garden Retreat would allow for sixteen trays!-------it is on my list of things to buy---sometime!
Right now I can only do up to 8 trays under lights.
I am just getting begonias, geraniums and petunias going now.
