Safer® Hydro FAQ: What Lights Are Best For Indoor Gardens?
The answer depends on what you're trying to grow.
Fluorescent lights work fine for starting seeds or clones, and may generate enough light for leafy greens and herbs. For flowering plants, LED and high-intensity grow lights produce better results. The two types of high-intensity lights differ in where they're strongest on the color spectrum, which affects how your plants grow.
Metal halide lights emit bluish-white light that stimulates lush green growth. High-pressure sodium bulbs emit light concentrated in the orange/red spectrum, which plants need for flowering and fruiting.
Incandescent lights are too hot for use in indoor gardens.