How to Grow with Metal Halide Industrial Lighting
- 1). Choose lights that can take both metal halide and high-pressure sodium bulbs so you can interchange them when your plants enter their flowering stage. Choose one with an external ballast so you can keep it in another room. Ballasts produce a lot of heat.
- 2). Measure the growing area to determine the bulb wattage and how far to hang the bulbs from the plants. The larger the growing area the higher the bulb wattage needs to be. For a growing area of 3 feet by 3 feet, use a 250-watt bulb. A growing area of approximately 4 by 4 feet needs a 400-watt bulb, an area 5 by 5 feet needs a 600-watt bulb and a 6-by-6-foot area needs a 1000-watt bulb.
- 3). Hang the lights from the ceiling using a pulley so they can be raised as the plants grow. Plug them into a timer. Set the timer for 12 to 16 hours of light per day. Plants need a period of darkness so they can rest and regenerate themselves.
- 4). Position the plants beneath the light. The higher the bulb wattage, the more heat produced and the further away from the light the plants have to be. For a 250-watt bulb, place the plants 18 to 24 inches away from the light. For a 400-watt bulb, put the plants 24 to 36 inches away, for a 600-watt bulb place the plants 36 to 48 inches away, and for a 1000-watt bulb the plants should be 48 to 72 inches away. If the tops of the plants turn brown, they are too close.
- 5). Use fans to vent your growing area and keep down the heat produced by the lights.
