These lights are typically small, easy to install, and relatively inexpensive. They contain two LED bulbs, one red and one blue. You’ll usually need one grow light for each plastic tub or every three to five feet of plastic pipe. Between them, the light emitted simulates sunlight better than your typical incandescent bulb. By their nature, LED lights don’t emit as much heat as traditional bulbs, which makes them easier to handle and less likely to interfere with the overall heat and humidity balance of the room. What they won’t do is help you see your plants well. You’ll want some normal bulbs around for human eyes.