Can I Use a Mercury Ballast With a Metal Halide Lamp?

Metal halide lamps are one of three types of high intensity discharge (HID) lamps in general use. The other two types are mercury and high-pressure sodium lamps. HID lamps have bright light output making them perfect for outdoor lighting.

  1. Ballasts

    • Ballasts are required for many kinds of lamps which build up resistance the longer they are lighted. These lamps, including fluorescent lamps and HID lamps, would continue to draw more and more current the longer they are lit. Eventually the bulb overheats and could possibly explode.

    Metal Halide Bulb with Mercury Ballast

    • You cannot use a mercury ballast with a metal halide lamp. The power supplied by a mercury ballast for starting and for cycling is different from the metal halides requirements and the mismatch can cause explosive failure of the metal halide lamp. Metal halide bulbs must be run using matching metal halide ballasts.

    Uses

    • Because they provide a wide light spectrum, metal halide lamps are often preferred for use in reef aquariums which need bright, high intensity light sources. For the same reason they are also frequently chosen for the indoor growing of plants. Other uses include applications that require bright outdoor lighting such as baseball stadiums and street lights.