LED grow lights are fairly new to the marijuana growing world, 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 skill, in addition to the quality of the lamp itself, but that's a good guideline for most models. For instance, a 200W LED (200W true power draw, not an "equivalent" wattage) would yield about 100-200 grams on average, or 3.5 to 7 ounces.
Today's LED models are far better for cultivating 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 produce 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 generally leads to healthier growth. Other spectrum colors like red, far red, and infrared are important for the budding/flowering stage. LED manufacturers have designed customized lenses to aim light directly to the plants and increase penetration, leading to bigger yields for the same amount of light compared to older models. There are also several form components, with everything from the casing to the size of the diodes varying from model to model.
3 Main Types of LED Grow Lights
There are 3 main types of LEDs that are most commonly used for growing cannabis. Each kind of model has its pros and cons, so there isn't yet a "ideal" LED type. Some are better for some situations 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.
The name "Quantum Board LED grow light" originated 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 give particularly good results 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, however they are set on a panel with "arms" like a spider instead of a solid board. One very popular example is the SPYDRx line of LED lights. These typically have an extremely high price, yet cultivators that utilize 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 tend to be more compact. Most LED grow lights offered today are in this style. They are sort 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 large COB (Chip on Board) LED "bulbs". Each COB is very bright and intense since they have multiple LED chips in a small area. COBs produce more intense light than other types of LEDs, and each COB uses a significant amount of electricity.
Rather than 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 gaining in popularity and are known for having deep penetration into the plant canopy.
It's also common to see LED grow lights that just have one COB per lamp. These make it easy to spread out your light over a grow area, one lamp at a time. Sometimes called "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 several AutoCOBs together. They are very configurable if you have an abnormally shaped grow area, or would like to be able to accommodate various plants of different sizes at the same time.Some COB LED grow lights can be connected to standard light outlets.
Choose LED Grow Lights If: