LEDs also typically run a lot cooler than HIDs, so you may not need extra equipment to cool down your grow space, and one LED can usually be used for both vegetative and flowering growth. Some high-end LEDs allow you to change the spectrum for each growth stage.
The typical homegrower will only need one or two lights. Most states limit grow amounts to 6 or 12 plants, and one or two lights should be plenty for that. If you plan on running two separate rooms, one for vegetative plants and one for flowering plants, you’ll need two lights.
There are daylight bulbs and warm white bulbs; the former better for vegetative growth, and the latter for flowering.
There are many types of lights, but below are the four most common you’ll find in a grow room. There are many variations within each of these four types as well, and new lights and technology come out all the time.
Best CFL grow light brands
These fluorescent lights are cheap and efficient and great for vegetative growth. They’re especially great for helping along germinating seeds and small seedlings because they don’t put off much heat and won’t scorch the delicate seeds. They won’t run up your electricity bill too much.
Consider how often you’ll be growing weed and how long it will take to pay off the initial investment—if you grow once a year, it’ll take a lot longer to pay off an expensive light than if you grow multiple harvests a year.
The downside to CFLs is they aren’t great for flowering plants, and growers will usually use another type of light to finish plants. CFLs just don’t generate enough intense light for plants to pack on weight.
Other considerations when choosing a cannabis grow light
Aside from the price of the actual light, also take into account utilities—all lights will add to your electricity bill every month, but some more than others. High-intensity discharge lights—known as “HIDs”—may be cheaper to buy but can gobble up electricity, whereas LEDs are more efficient and kinder on your electricity bill but usually more expensive to buy.
Make sure you have enough outlets and power available in your breaker board for your grow space to comfortably accommodate all equipment. Figure out all pieces of equipment, such as lights, fans, possibly an AC or dehumidifier, and calculate how much power they’ll require. You’ll be running this equipment every day for months, so if you don’t have enough power it can be dangerous. Never overload an electrical outlet.
Note 2: Incandescent light bulbs (old fashioned light bulbs) are NOT suitable for growing marijuana!
Cannabis plants under a T5 grow light – when plants are trained (like these ones in a Scrog setup) you can get pretty decent yields from fluorescents.
That being said, when it comes to the flowering/budding stage, if you can fit a bigger light you will get significantly better yields/watt by using an HID or LED grow light!