Grow lights are the key to a great indoor garden. Choosing a hydroponic light is the single-most important decision you will face when setting up your growspace.

HID grow lights are more efficient and produce more light (up to 10x more lumens/watt than an incandescent light), but also produce more heat, are more expensive, and will require the additional maintenance and expense of a ballast. To make your indoor gardening system more efficient, you should consider using a reflector.

The most popular sizes of garden grow lights are 100W, 250W, 400W, 600W, and 1000W. A good general rule is that each light will cover a certain square area based on their wattage output. You can use reflectors to shift some of this light to other areas, but this square area is where your light will produce the most light, so it is a good benchmark for planning your indoor garden"s design. Here is a list of the expected coverage areas for the more popular sizes of HID grow lights:

100W = 2" x 2" | 250W = 3" x 3" | 400W = 4" x 4" | 600W = 5" x 5" | 1000W = 6" x 6"