Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

plates stuck together by resin and wound with copper wire. The capacitor can is on the right under the connecting wires.
    More economical ballast kits contain a transformer core, capacitor (HPS and some metal halides), starter, containing box, and, sometimes, wire. You can purchase components separately from an electrical supply store, but it’s a bigger hassle than it’s worth. If unfamiliar with electrical component assembly and reading wiring diagrams, purchase the assembled ballast in a package containing the lamp and hood from one of the many HID distributors.

The above bar graph shows the lumens-per-watt conversion of different lamps. Notice that except for the 600-watt HPS, the lumens-per-watt conversion factor increases with higher wattage bulbs. The lumens-per-watt formula is used to measure the lamps’ efficiency – the amount of lumens produced for the quantity of watts (electricity) consumed.
    Do not buy used parts from a junkyard or try to use a ballast if unsure of its capacity. Just because a bulb fits a socket attached to a ballast, does not mean that it is the proper system. One of the most miserable gardens I have ever seen was grown with mercury vapor streetlights and makeshift reflective hoods. The grower was low on money, so he pilfered all the street lamps, ballast and all, in front of his house.
    Even though HIDs have specific ballasting requirements, the ballasts have a good deal in common. The most common characteristics ballasts share are noise and heat. This noise could drive some people to great fits of paranoia! Ballasts operate at 90-150°F (32-60°C). Touch a “strike anywhere” kitchen match to the side to check if it is too hot. If the match lights, the ballast is too hot and should be taken into the shop for assessment. A ballast that runs too hot is noisy and could cause problems or burn out. Heat is the number one ballast destroyer. Many ballasts are manufactured with a protective metal box. This outer shell safely contains the core, capacitor (starter), and wiring. If you build another box around a ballast to dampen noise, make sure there is plenty of air circulation. If the ballast runs too hot, it will be less efficient, burn out prematurely, and maybe even start a fire!

Reflective walls are easy to set up.

Movable reflective walls are easy to remove for maintenance, and they give the maximum reflection.

Plastic Visqueen is easy to clean, and it covers walls completely.

Insulated greenhouse mobile blankets also make great grow room partitions.

Ballast designs are more simple now than ever before. Above, you see two new European ballast designs.

The ballast is attached to the bulb and reflective hood in this greenhouse fixture.

Attach ballasts to the wall on a plank for easy inspection and troubleshooting.

Place ballasts up on shelves so they stay out of the way and out of the splash-range of water.
    More expensive ballasts are equipped with ventilation fans to maintain cool operating temperatures. Air vents allow a ballast to run cooler. The vents should protect the internal parts and prevent water from splashing in.
    Some industrial ballasts are sealed in fiberglass or similar material to make them weatherproof. These ballasts are not recommended. They were designed for outdoor use where heat buildup is not a problem. Indoors, the protection of the sealed unit from weather is unnecessary and creates excessive heat and inefficient operation.
    A handle will make the ballast easy to move. A small 400-watt halide ballast weighs about 30 pounds (14 kg), and a large 1000-watt HP sodium ballast tips the scales at about 55 pounds (25 kg). This small, heavy box is very awkward to move without a handle.
    Most ballasts sold by HID stores are “single tap” and set up for 120-volt household current in North America or 240-volts in Europe, Australia, and New Zealand. North American ballasts run at 60 cycles per minute, while European, Australian, and New Zealand models run at 50 cycles per minute. A ballast from Europe, Australia, or New Zealand will not work properly at 60 cycles per minute. Some “multitap” or “quad-tap” ballasts are ready for 120 or 240-volt service. Single-tap ballasts accommodate only one voltage, usually 120. Multi-tap ballasts accommodate either 120 or 240-volt service.
    It is generally easiest to use the regular 120-volt systems, because their outlets are more common. The 240-volt systems are normally used in Europe, Australia, and New