LED grow lights are fairly new to the cannabis growing world, but they have become extremely popular over the last few years with their ability to produce excellent yields while staying cool and using a reasonable amount of electricity. With a quality LED grow light and an average-to-good grow, you can expect yields of around 0.5 to 1g/watt.
The ultimate yield depends a lot on strain and grow ability, as well as the quality of the lamp itself, but that's a good rule of thumb for most models. For example, a 200W LED (200W true power draw, not an "equivalent" wattage) would produce about 100-200 grams on average, or 3.5 to 7 ounces.
Today's LED models are much better for growing marijuana than the ones available even a few years ago. Many modern lamps are full spectrum or "wideband" spectrum (instead of just red and blue light diodes, which generate a bluish purple light and are occasionally called "blurples"). Full spectrum light is easier on the eyes and adding at least some amount of green light to blurples typically leads to healthier growth. Other spectrum colors like red, far red, and infrared are important for the budding/flowering stage. LED manufacturers have designed specialized lenses to aim light directly to the plants and increase penetration, leading to greater yields for the same amount of light compared to older models. There are also many different form factors, with everything from the casing to the size of the diodes varying from model to model.
3 Key Types of LED Grow Lights
There are 3 key types of LEDs that are most often utilized for cultivating cannabis. Each kind of model has its advantages and disadvantages, so there isn't yet a "best" LED type. Some are better for some circumstances than others.
1. Spread Style
Several smaller LEDs are spread out over a large area. Examples of this style include Quantum Boards, Rack and "Spider style" LED grow lights.
The name "Quantum Board LED grow light" emerged from Horticulture Lighting Group, though the term is now occasionally used for any LED in this style. They tend to have relatively low wattage diodes which are spread out over a large area on a board. These are getting more popular lately, and appear to provide particularly good results for the amount of wattage used.
The "spider style" LEDs are similar to Quantum Boards because the individual diodes are spread out and tend to be on the smaller side, but they are set on a panel with "arms" like a spider rather than a solid board. One very popular example is the SPYDRx line of LED lights. These typically have an extremely high cost, but growers that use them swear they get better outcomes than any other type of LED grow light.
2. Traditional Panel
The conventional panel LEDs have small to medium wattage diodes and the lamps tend to be more compact. Most LED grow lights offered today are in this design. They are sort of halfway between a Quantum Board and a COB Style light, with a mix of features from both.
3. COB Style
These grow lights use large COB (Chip on Board) LED "bulbs". Each COB is extremely bright and intense because they include multiple LED chips in a small area. COBs produce more intense light than other kinds of LEDs, and each COB utilizes a considerable amount of electricity.
Instead of having dozens of small diodes, COB style LED grow lights generally only have a handful of huge COBs, each with strong lenses to point the light down into the plant. These are quickly growing in popularity and are known for having deep penetration into the plant canopy.
It is also common to see LED grow lights that only have one COB per lamp. These make it easy to spread your light over a grow space, one lamp at a time. Occasionally known as "AutoCOBs". Some LED grow lights have a single COB LED. Multiple units can be spread out as needed.
Each COB has its own spectrum, so you can make a customized spectrum for your plants by combining multiple AutoCOBs with each other. They are very configurable if you have an abnormally shaped grow area, or would like to be able to accommodate different plants of various sizes at the same time.Some COB LED grow lights can be plugged into standard light sockets.
Choose LED Grow Lights If: