High Intensity Discharge (HID)
Like hydro, you can think of HID (high intensity discharge) lights as the big dogs and the lights most professionals use. They produce the best marijuana and have the highest yields. There are three main types of HIDs.
Metal Halide (MH)
Mainly for the vegetative state as they produce a white/blue light (6500K).
High Pressure Sodium (HPS)
Best for flowering as they produce a yellow light (2500K). If you have to pick between an MH or HPS, pick HPS as yellow light during the entire grow will be better than white.
Ceramic Metal Halide (CMH)
The best of the three and works great throughout entire grow from seed to harvest.
Less maintenance: Since these lights are so powerful you can and should keep your plants decently away from the lights. This creates less work compared to CFLs.
Moderate setup time: A lot of HIDs come prepackaged as a kit that cut way down on setup time.
HID lights need a ballast to start and regulate the lamp and its current, which adds to the setup, as well as introduces a stealth issue. Digital ballasts caused EMI (electromagnetic interference) or RFI (radio frequencies interference) and this can mess with electronics in your house and your neighbor's house, especially their cable. They can experience poor TV reception which turns to them calling the cable guy, who will see that the issue is coming from your house.
Police can also potentially find you with a simple AM radio, which is a way you can check it you have a problem. You can buy an older style magnetic ballast and you’ll be fine, but digital ballast is preferred as they are more efficient. If you buy a digital/electronic ballast make sure it has a RF (radio frequency) shield.
Expected cost: You can grab a 600w HID system off Amazon for around $160 that includes reflector hood, bulbs, timer, and ballast which you will all need. You can replace a 600 metal halide bulb for around $20. As you can see it’s not the bulbs per say that are expensive, it’s just the requirement of a hood and ballast that run up the initial cost.