Metal Halide lights are a big part of most grow operations, due to their efficiency and the fact that they have worked well for thousands of growers. Your plants need light, obviously, and metal halide lights are a great way to make sure that they get them. There are two major phases to that grow operation, red and blue, and metal halide lights provide much more in the blue spectrum, which is great for vegetative growth of your plants. Using the right kind of lighting is always important, so I’ll cover the basics to make sure that you know what you’re in for.
What Are Metal Halide Grow Lights?
These are lights that will provide a fantastic amount of light that will help your plants thrive and grow to their fullest. They are HID lights, which are small, but incredibly intense, and are more efficient than both fluorescent and incandescent bulbs. Whether you are using hydroponic or soil, that means that these can be a great addition to your grow room.
There are several parts that make up metal halide grow lights. Tungsten electrodes connect with quartz arc tubes and this is where the light is produced. That arc tube, though, includes special mercury vapor and other metals and gasses that come together to create the brilliant light that helps your plants grow. A glass bulb surrounds that tube and a metal base connects it to the power supply. Also, some metal halide lights might use a tube that is made from aluminum oxide or alumina, but those are not the most common. In order to function properly, this all has to be powered consistently and in a way that provides reliable power, like that of a ballast.
All grow lights put out a different kind of light. On the spectrum of lighting, Metal halide grow lights register an 80 on the color-rendering index and this means that there is very high quality white light in the output. The actual color temperature of metal halide grow lights registers between 3,000k and 20,000k. That is a huge range, but 20,000k is important because it marks the blue end of the spectrum.
During the vegetative stage of your plant’s life, this is the most important part of the spectrum. There are some lights that produce the entire spectrum, but much of that light will be wasted if it isn’t something that your plants’ need. During the vegetative stage, your plants will be growing large stems and leaves that will support the buds once you enter the flowering phase. Without taking care of your plants during this vegetative stage, they will not be able to hold up their flowers and your plants will be unable to transport nutrients the way that they should, making sure that they are always healthy. This phase is when long days would naturally provide the plants with up to 17 hours of light. Metal halide grow lights are your way of reproducing that daylight and are suited well for the job.
Using The Lights Properly
The biggest thing that you have to take into account when using metal halide grow lights properly is the heat and the distance from your plants. These are a very powerful kind of lights and you should never have them too close. The normal range is from 250 watts to 1000 watts, any of which can be great for vegetative growth. For example, a 250 watt light bulb should be 10 inches away from your plants, with the distance growing as the wattage increases. You should always keep a thermometer handy when growing with metal halide grow lights because it can be easy to burn your plants. You’ll also need to properly vent the grow room due to the temperature. If you are growing in a cooler environment this might not be a problem, but for warmer climates this kind of heat can pose serious problems.
Once you have achieved the kind of vegetative growth that you are looking for, you’ll also need to think about how you will provide your plants with the red spectrum light that they need for flowering. Many people switch to HPS lights at this point, but there are other options available as well. Those will also pose heat problems, however, so always be careful and always ventilate your grow room! Use a carbon scrubber if you are worried about the smell.
The final thing that you need to know about metal halide lights is that they are not ideal for beginning stages of growth. Clones can either grow too quickly for their own good or be burned, both of which can be devastating to a growth cycle.
At the end of the day, metal halide grow lights are an incredibly important part of any grow. Providing this kind of quality light to your plants makes sure that they grow up healthy and strong, but you only have to pay attention to the heat and you will be perfectly ok.