In our ongoing series on how to grow pot, we’ve talked about basic equipment and materials, different growing systems, reverse osmosis water, selecting the right place for your indoor grow room, and other important topics.
In this article, we talk about marijuana grow lights.
We’re only going to talk this time about the most popular type of grow lights: High Intensity Discharge (HID).
These are the grow lights most indoor marijuana growers have been using for the past 30 years.
They have several components: a reflector or hood, a ballast, a power cord, a cord that goes from the ballast to the bulb assembly, and grow bulbs.
Some growers run HID grow lights without a reflector or hood, but that wastes light and electricity, and it’s not safe.
Reflectors and hoods come in a variety of shapes and sizes that have big impact on your grow room costs and your marijuana plants.
Definitely read this comprehensive article on grow lights reflectors and hoods.
The two main categories of reflectors and hoods are cooled versus non-cooled.
Cooled reflectors are sealed so that an inline exhaust fan sucks bulb heat out of the grow room.
Bulb heat is intense. If it’s not sucked out of your cannabis grow room, your air conditioner will have a lot more expensive work to do.
Some reflectors have a clear glass pane on the bottom and another kind has no glass pane on the bottom.
The glass pane cuts down on light intensity and wavelengths, but partially insulates grow bulb heat from your plants and provides safety.
You don’t want to touch an HID bulb while it’s lit.
You can get severe burns.
You also don’t want an HID bulb to get anywhere near to touching your plants or anything else in your grow room.
HID bulbs come in two general types:
- Metal halide (MH) bulbs have a summer sun spectrum and are used primarily in grow phase.
- High pressure sodium bulbs have an autumn sun spectrum and are used primarily in bloom phase.
“Double-ended” high pressure sodium bulbs are gaining popularity because they’re electricity-efficient, extremely intense, and can create huge yields.
Problem is, double-ended bulbs are very hot and can easily burn your cannabis plants, so you shouldn’t use them unless you have ten-foot ceilings.
There are two types of ballasts for HID lights: magnetic core and coil, and digital.
Digital ballasts are by far the most efficient, reliable, and electronically precise for powering bulbs so you get the full light spectrum your bulbs are designed to put out.
Magnetic core and coil ballasts are noisy, they waste energy, they might compromise bulb output and life span, and are so heavy you could use them as boat anchors.
As with all sectors of the hydroponics grow equipment industry, a lot of HID ballasts, grow bulbs, and reflectors are not worth buying.
The only manufacturer of grow bulbs and ballasts we confidently recommend is Hortilux.
Please consult the article we linked to earlier so you see how to find quality reflectors and hoods.
The other thing you need to know is that grow bulbs come in different wattages: 250, 400, 600, and 1000.
We use 1000 or 600-watt bulbs because those are good for full-size marijuana plants in a full-size grow room.
You can get digital ballasts with adjustable wattages, and some of these adjustable digital ballasts have a feature that overdrives a 1000-watt bulb to push it to a slightly higher light output.
A 1000-watt bulb will provide enough light for 16-20 square foot grow space, and if you’re doing everything right, you’ll get two or more pounds of dried bud per light every time you harvest.
If you’re choose 250 or 400-watt bulbs, you’re have a smaller grow space, not much bigger than a closet.
There are other types of grow lights (LED, ceramic metal halide, and fluorescent) that we’ll talk about in future articles, so stay tuned to BigBudsMag.com—the only marijuana magazine created by growers for growers.