The bottom line that I can share with you, from my perspective where I get visibility to lots of opinions on the topic, see lots of sales and growth cycles, talk to lots of growers, is this: We are still in the investigative and development stage with LED technology in this sector.
There is a lot of information out there on the internet from various growers and lighting suppliers. You can find a contradiction to almost every point you find! Most growers agree that for young plants through the veg stage of growth you will want to have a light source with a good amount of blue light or even white (full spectrum) lighting. The main reason for this is to reduce internode stretching to produce a stockier, healthier plant.
No manufacturer , supplier, or customer can state they know the optimum LED recipe for cannabis (or tomato’s, or cucumbers, or orchids, etc.) as nobody has tested and tried multiple, different spectrums with each one being tuned to a specific strain or cultivar of each plant type to be able to render a quantifiable opinion.
When comparing both technologies, always compare light levels of the entire grow and not just fixture to fixture. I cannot stress enough that there is no such thing as a 1-for-1 replacement of HPS by LED! That simply does not exist in the marketplace. Yes, there are LED fixtures that exist when measured directly beneath the fixture. The output looks equal to or even greater than an HPS. But, when you move the PAR sensor any direction from centered beneath the LED the light level decreases much more under the LED than any HPS fixture!
There is a big misconception in the industry stemming from the LED suppliers that the ability to have your LED lights so much closer to your crop will help increase production lower into the crop. This could not be further from the truth! When your light source is closer to the top of the canopy than the shadows created from the top layer of leaves are much bigger than if the light was further away. (Use a flashlight and make a shadow on a wall with your hand. Watch how the shadow grows as you get the light closer to your hand). Also, light penetration into the crop comes from the crossover between fixtures.
Unpacking Existing Information
This is a big consideration to consider when comparing these technologies. There is no easy math to calculate an ROI for this but when comparing light plans from one source of light to another be sure to take into consideration the distance of the light source from the canopy.
There are daylight bulbs and warm white bulbs; the former better for vegetative growth, and the latter for flowering.
These fluorescent lights are cheap and efficient and great for vegetative growth. They’re especially great for helping along germinating seeds and small seedlings because they don’t put off much heat and won’t scorch the delicate seeds. They won’t run up your electricity bill too much.
CFLs (compact fluorescent lamps) are fluorescent lights similar to what you’d find in a school or office building, but smaller. For growing weed, they are usually called “T5s”—the “T” stands for “tubular” and the “5” refers to its diameter, “⅝”.
You can find lights for under $100, but they may be low quality and not produce the right spectrum of light, and you can also easily spend as much as $2,000 for a large, state-of-the-art LED.
HPS (High-pressure sodium)
New LED grow lights come out all the time, but knockoffs abound. There are a lot of cheap LEDs that don’t produce the right spectrum of light for plants.
Lights have fixtures and bulbs, and some require a ballast. Depending on the type and model, the bulbs or the fixtures can be more expensive. There are a lot of abbreviations, but don’t be alarmed.
One of the crucial elements a cannabis plant needs is light. During photosynthesis, a plant converts light energy into chemical energy, allowing it to grow strong and healthy, and with cannabis in particular, light also fuels bud production.
Best HID grow light brands
The typical homegrower will only need one or two lights. Most states limit grow amounts to 6 or 12 plants, and one or two lights should be plenty for that. If you plan on running two separate rooms, one for vegetative plants and one for flowering plants, you’ll need two lights.
LEDs (light emitting diodes) are relatively new to the cannabis growing world, compared to HPSs, MHs, and CFLs, but they are quickly proving to be the way of the future. LEDs may be more expensive to buy initially, but they are far more efficient and kinder to the environment and your electricity bill. Some cities even give tax breaks to commercial growers who install or switch to LEDs because they’re better for the environment.