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!
Ceramic Metal Halide (CMH) & Light Emitting Ceramic (LEC) Grow Lights
HIDs are very well suited to growing cannabis and very easy to use once they’re set up. If your main goal is to get the highest yields possible, then HIDs are the way to go! However, they do require extra setup compared to the other grow lights because chances are you will need a fan to vent out heat from your grow space.
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.
- Fluorescent grow lights get smaller yields per watt than the other types of grow lights if you use them in the flowering stage while buds are forming. With fluorescents you can expect about 0.25 grams of buds for every watt of electricity (using the true watts out the wall, not any type of “equivalent” watts), while LEDs and HPS get 2-4 times as much yield per watt of electricity.
- The light from a fluorescent lamp doesn’t penetrate far down into the plant so they are best suited to plants that have been trained to grow short and flat; they aren’t powerful enough to support tall plants in the flowering stage.
More Light = Bigger Yields!
(up to a point, it is possible to give your plant too much light!)
Metal Halide grow lights are generally used for the vegetative stage because they produce a bluish light that vegetative plants love, though this type of light can also be used all the way to harvest.
Keeping CFLs close results in the best yields and growth
There is a larger size MH/HPS grow light available (1000W), but at that size it starts going outside the scope of a “hobbyist” grower as far as ease and yields. In addition to needing a lot of extra cooling which costs electricity, a 1000W HPS grow light is less efficient compared to a 600W grow light (as far as how much light is put out for electricity used). I think most hobbyist growers would be happier with a 600W, or even two 600W lights, over a 1000W 🙂
There many grow lights that work well for growing cannabis indoors, but they boil down to 3 popular types: fluorescents (CFLs, T5s), HIDs (MH, HPS, LEC) and LEDs. Learn the differences so you can pick the best option for your setup!
Use T5 flourescent grow lights for cloning, propagation, and seedling stages
While each of these options has pros and cons, as well as different stages of growing cycle and different sizes of operation they work best for, in this article we’ll focus more on the types that will be your bread-and-butter for a commercial-scale grow operation.
To understand the climate and temperature that your plants need, check our article on air flow and ventilation which will teach you how to keep the right temperature in your sealed room.
HPS and Metal Halide lights will get very hot and you want to use them with an exhaust fan to not burn your plants.
There are 4 main types of lamps that you can use for growing cannabis:
However in the vegetative and flowering stages, keep in mind that fluorescents will lead to smaller yields. While T5 lights are great for small plants, in the later stages you will want to use a higher powered light like HPS or Metal Halide.
These bulbs, along with High Pressure Sodium (HPS), the other type of HID grow light, produce the highest yields per watt of electricity out of any grow lights available. For this reason, they are the go-to for professional growers in the later stages of plant development.
Fluorescent grow lights (T5 and CFL)
Gently switch from one cycle of light to the other. Take a couple of days to switch from 18/6 to 16/8 to 14/10 to 12/12 hours.
Lights determine your marijuana plants' grow cycles, photosynthesis, health, and the quality of their buds. Which Lights are Best for Growing Weed? There are 4 main types of lamps that you can use for growing cannabis: LED grow lights, Fluorescent grow lights (T5 and CFL), Metal Halide grow lights, and High Pressure Sodium grow lights.