HID lights most closely mimic sunlight, and they make excellent lights for using when growing plants hydroponically. HID stands for High Intensity Discharge, and it puts out a very bright full spectrum light. The light spectrum is important depending on what growth stage your plants are in. Young plants need blue light, whereas when you need your plants to flower and fruit they perform best under red and orange light. Providing both of these types of lights in one light bulb will provide your plants with everything they need in terms of light appropriate for any stage of plant growth.

These grow lights come in two different types. Metal halide HID lamps come in some varieties featuring blue light and some that offer more in the red/orange light spectrum. Metal halides are sometimes less expensive than other HID lights. High Pressure Sodium bulbs put out a great light in the red, orange and yellow spectrum. They last twice as long as metal halide light bulbs, and emits a brighter light.

Reflectors are also used in conjunction with grow lamps. Some plants prefer a concentrated light, while others prefer a more diffused light, and you can find reflectors that will produce either of these effects.

If you choose HID lights you will also need to use them along with electronic ballasts or digital ballasts. A ballast controls the flow of current that goes into an electrical circuit. This ballast is used to start and operate the HID light bulb. Because HID lights run at such a high intensity, it needs the ballast to control the electrical current flow.

Another type of lamp that always requires a ballast is the fluorescent light. It uses mercury vapor in a gas that is activated by the addition of electricity, causing it to give off visible light. These bulbs contain warm and cool spectrums of light, and they are also a great option for lighting your plants that you are growing hydroponically. They are typically less expensive than HID lights, but they also do not put out as much light as an HID lamp.

Plants do well when they are under light for the appropriate amount of time, usually 14 to 15 hours per day. You can put them on a timer so they come on and go off without you having to think about it. The light available to your plants is crucial to their ability to thrive and flourish, so don't skimp on light.