LED grow lights are relatively new to the cannabis growing scene, but they have become extremely popular over the last few years with their ability to produce great 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 about 0.5 to 1g/watt.
The final yield depends a lot on strain and grow ability, in addition to the quality of the lamp itself, but that's a good guideline for most models. For example, a 200W LED (200W true power draw, not an "equivalent" wattage) would yield around 100-200 grams on average, or 3.5 to 7 ounces.
Today's LED models are much better for cultivating marijuana than the ones available even a few years ago. Several modern lamps are full spectrum or "wideband" spectrum (rather than just red and blue light diodes, which generate a bluish purple light and are sometimes called "blurples"). Full spectrum light is easier on the eyes and adding at least some amount of green light to blurples usually leads to healthier growth. Other spectrum colors like red, far red, and infrared are important for the budding/flowering stage. LED manufacturers have created customized lenses to aim light directly to the plants and increase penetration, resulting in 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 differing from model to model.
3 Key Types of LED Grow Lights
There are 3 key kinds of LEDs that are most commonly used for growing marijuana. Each kind of model has its pros and cons, so there isn't yet a "ideal" LED type. Some are better for some circumstances than others.
1. Spread Style
Several smaller LEDs are spread out over a large space. Examples of this style include Quantum Boards, Rack and "Spider style" LED grow lights.
Quantum Board
The name "Quantum Board LED grow light" originated from Horticulture Lighting Group, though the term is now sometimes used for any LED in this style. They tend to have fairly low wattage diodes which are spread out over a large area on a board. These are becoming more popular lately, and seem to give particularly good outcomes for the amount of wattage used.
Spider LED
The "spider style" LEDs are similar to Quantum Boards in that 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 popular example is the SPYDRx line of LED lights. These typically have an extremely high cost, but cultivators that use them swear they get better results than any other kind of LED grow light.
2. Traditional Panel
The standard panel LEDs have small to medium wattage diodes and the lamps have a tendency to be more compact. Most LED grow lights available today are in this design. They are kind of halfway between a Quantum Board and a COB Style light, with a mix of elements from both.
3. COB Style
These grow lights use huge COB (Chip on Board) LED "bulbs". Each COB is incredibly bright and intense because they have multiple LED chips in a small area. COBs generate more powerful light than other types of LEDs, and each COB utilizes a considerable amount of electricity.
As opposed to having dozens of small diodes, COB style LED grow lights generally just have a handful of large COBs, each with strong lenses to direct the light down into the plant. These are rapidly growing in popularity and are known for having deep penetration into the plant canopy.
AutoCOBs
It is also typical to see LED grow lights that only have one COB per lamp. These make it easy to spread your light over a grow area, one lamp at a time. Sometimes referred to 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 create a custom spectrum for your plants by combining several AutoCOBs together. They are very configurable if you have an abnormally shaped grow area, or want to be able to accommodate various plants of different sizes at the same time.Some COB LED grow lights can be plugged into regular light sockets.
Pick LED Grow Lights If: