LED grow lights are fairly new to the marijuana growing world, but they have become wildly 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 high quality LED grow light and an average-to-good grow, you can expect yields of around 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 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 far better for growing cannabis than the ones available even a few years ago. Several modern lamps are full spectrum or "wideband" spectrum (as opposed to only 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 including at least some amount of green light to blurples typically results in healthier growth. Other spectrum colors like red, far red, and infrared are important for the budding/flowering stage. LED producers have designed customized lenses to aim light directly to the plants and enhance penetration, leading to bigger yields for the same amount of light compared to older models. There are also various form components, with everything from the casing to the size of the diodes varying from model to model.
3 Key Kinds of LED Grow Lights
There are 3 main types of LEDs that are most often used for cultivating cannabis. Each type of model has its benefits and drawbacks, so there isn't yet a "best" LED type. Some are better for some situations 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 currently 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 offer particularly good outcomes for the amount of wattage used.
The "spider style" LEDs are similar to Quantum Boards in that the individual diodes are spread out and have a tendency to be on the smaller side, but they are set on a panel with "arms" like a spider instead of a solid board. One popular example is the SPYDRx line of LED lights. These typically have an extremely high price, yet growers who utilize them swear they get better outcomes than any other kind of LED grow light.
2. Traditional Panel
The conventional panel LEDs have small to medium wattage diodes and the lamps have a tendency to be more compact. Most LED grow lights offered today are in this design. They are kind 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 incredibly bright and intense because they include multiple LED chips in a small area. COBs produce more powerful light than other kinds of LEDs, and each COB uses a considerable amount of electricity.
Instead of 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.
It's also common to see LED grow lights that only have one COB per lamp. These make it easy to spread out 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. Several units can be spread out as needed.
Each COB has its own spectrum, so you can make a custom 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 various plants of various sizes at the same time.Some COB LED grow lights can be plugged into standard light outlets.
Pick LED Grow Lights If: