While there are many types of grow lights available, HPS (High Pressure Sodium) grow lights are most ideal for flowering and fruiting purposes. This is because of the fact that HPS lights emit light on the red and orange spectrums, which are ideal for these purposes. They consist of a ballast, reflector, and large glass bulb which contains sodium. HPS grow lights are intended to be supplemental, not take the place of natural sunlight.
HPS grow lights require a small power transformer called a ballast to operate. This ballast plugs directly into a wall outlet for power, and is connected to the reflector with a waterproof cable. The wattage of the ballast governs how powerful an HPS bulb you can use in the system. The higher the wattage, the more area you can cover with a single light. Your typical consumer grade ballast runs on either 120v or 240 v and ranges from 100W to 1000W. When you select a ballast, be sure to also select a compatible reflector and bulb which can handle the chosen wattage.
HPS grow light bulbs are quite expensive, but this is because they are specialty bulbs. They are designed to only release colors in the orange and red spectrums which are ideal for boosting plant growth during their flowering stage. Some HPS bulbs have increased power along with the ability to release blue light, making them more all-purpose. As stated above, your HPS bulb should be selected based on the power of the ballast. They may look quite a bit different from a regular bulb, but they screw in the same way. HPS grow lights should be used to supplement plant growth during flowering and will not take the place of sun exposure.
Frequently fashioned out of aluminum, HPS grow light reflectors serve the purpose of holding the bulb and reflecting its light into a potent beam. The reflector is typically held several feet about the ground, mounted to a chain or cable. The easiest types of reflectors to use are the ones which have the power cable already installed. Some branded reflectors are only compatible with like-branded ballast power supplies. In many cases, the HPS light will be covered by a glass panel which hinges open for access. The glass panel prevents condensation from building up around the bulb and electrical components.
- Learn about LED grow lights.