@rickcorey do you think a shop light with 4 bulbs 6500kelvin hung from ceiling in my6 x 8 GH would provide enough light for the spinach and other plants, or do I really need several lights that I can hang on the shelves just above each long planter (more costly and setup). I just have things me herbs, spinach, arugula, radishes. That kind of stuff. But it's all growing really slow. Would one ceiling light with the four bulbs solve my need?