If you’re looking for a high-intensity, high-efficiency lamp for your indoor garden, an ideal choice for you are metal halide grow lights. These small lamps have proven to give indoor gardeners great results, particularly if they are in the process of growing larger plants.

Metal halide grow lights can be the best choice for plants larger than 2 feet tall. When plants get to this size, they start to require a light source that is more powerful than that of a fluorescent or incandescent grow light.

Metal halide grow lights emit a high-intensity discharge light, which is very bright and is many times used for security at properties like stadiums, construction sites, and parking lots. Bulbs with this amount of intensity to create a growing rich environment for larger plants to flourish.

Because of the high intensity light given off by a metal halide bulb, growers need to be sure and place them further away from their plants than other bulbs. Using a thermometer to keep track of the temperature is extremely important here. By placing MH bulbs at least ten inches away from your plants, you help protect them from getting to too hot and suffering heat damage.

There is one particular precaution when using metal halide grow lights. During the later stages of vegetation, plants are getting stronger and preparing to support flowers or fruit. Using the metal halide grow lights too early may allow your plants to grow faster but they could be missing out on the necessary strength development to bear flowers.

Following these few steps and combining them with the proper air temperature and circulation, metal halide grow lights will likely produce terrific results. These bulbs are designed to promote photosynthesis, and you will be able to have more control over your overall plant size.

Further illustrating the high-quality of light produced by these grow lights is the fact that metal halide bulbs score an 80 on the color-rendering index. The index ranges from zero to one hundred, with the best score rating being 100. The 80 rating is considered a very good rating for white light.

Grow lights are also rated based on their correlated color temperature. Metal halide grow lights can range from 3,000 Kelvin (yellow) to 20,000 Kelvin (blue) on this spectrum. Ideally, indoor gardening lamps will be very close to 6,500 Kelvin, which is the color temperature of daylight; so consider that when choosing lamps for your garden.

Gardeners should also consider where the light produced by their grow light falls on the electromagnetic spectrum. Blue light is said to be best for growing leafy vegetation, while red and orange light are best for growing flowers.

It’s interesting to note that there are several components that make up the metal halide grow light and contribute to the high-quality of light: An arc tube made of quartz, alumina or aluminum oxide, noble gas and mercury vapor that produce the light, a glass bulb, a metal base, a ballast which controls the current flowing through an arc tube, tungsten electrodes connected to the arc tube, and a power connection.

Some growers opt to keep the metal halide ballast outside the growing area because of the heat it produces. That approach is typically not a problem as the ballast can be connected with some wiring without needing an electrician. Any good quality metal halide grow package should include a ballast.

A few more things to think about before making a purchase of metal halide growth lights:

The wattage available for this type of grow light are: 150, 175, 250, 400, 600, 1000, 1100.

A bulb life expectancy of around 12,000 hours.

Recycle factor: Metal halide lamps and ballasts can be recycled at specialty recycling centers.

Before you shop for another grow light, you need to check out Frank Dixon’s articles all about metal halide bulbs, and the popular600 watt grow light, and his other grow light articles with full articles on LED grow lights, fluorescent and T5 grow lights, and the versatile cfl grow light.