Buying your first light-emitting diode (LED) light is exciting but often confusing since there are many styles of LED configurations, color spectrums, and brands. Growers love LED lighting because it offers less power consumption, a lower heat signature than high-intensity discharge (HID) systems, and many more benefits. The many options are why numerous factors go into the decision to buy LED lights for growing cannabis. If you’re searching for your best LED Grow light option, we’ve created this LED light buyers’ guide to help.
- Why choose LED grow lights?
- How do I choose an LED grow light?
- What is the best grow light for beginners?
- What color LED is best for plant growth?
- Does the quality of the build material matter?
- How easy are LED lights to use and install?
- Consider the warranty before buying!
- Three main types of LEDs
- What are the guidelines for grow lights?
Why choose LED grow lights?
HID systems have been the industry standard for decades, using either metal halide (MH) or high-pressure sodium (HPS) bulbs. However, in the past ten years, LED technology has come a long way thanks to lighting companies’ spending on research and development dollars in response to home cultivation’s popularity.
Consumer-level LED lighting now offers higher-intensity light at less wattage than HID systems. Plus, prices continue to fall, even as performance increases. Some models allow growers to custom-tune light spectrums, giving the grower full control. Heat dissipation is more efficient, light distribution is more effective, and the lifespan is significantly longer with LED lighting.
How do I choose an LED grow light?
A few limiting factors will exist when buying LED lights for growing weed. First, you’ll need to know what budget you are working with. LED lighting tends to be bunched into three price categories; budget, mid-level, and commercial. Second, what will the footprint of your grow be? Is it a 4×4 square, a 2×4 rectangle, or something different? You’ll need a light that fits best in the space you’ll have.
What features do you want? I wouldn’t choose one without a dimmer, but the range of features and connectivity will vary between the popular options. You’ll also need to consider available wattage at the wall. Are you using multiple lights and power intensive grow equipment? Add up the wattage and check the circuit breaker to ensure it can safely handle the load.
For an in-depth LED grow light specification guide, check out our LED grow lights for cannabis article.
What is the best grow light for beginners?
The answer to what’s best will always vary depending upon several factors. However, this buyer’s guide for LED grow lights will give new growers the confidence to decide which light they consider best. Sometimes, what makes a product the best is the physical unit and the support and information you receive from a company after the purchase.
Buying LED lights for growing marijuana is a big but necessary first step. As part of this LED grow light guide, we’ve outlined a few of the variables experienced growers consider when purchasing their next LED grow light.
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How many plants are you planning to grow?
This answer will not only determine the size of grow tent or area needed, but it also directly relates to the power of your light. Knowing how many cannabis plants you intend to grow will help you find an LED light with the desired coverage area.
To understand how important lighting is for healthy growth, read our article on maintaining optimal lighting for cannabis plants.
How many watts of LED grow lights do I need?
When using HID systems, the old math said 50W per square foot, or roughly 500W per square meter. LED lighting is more efficient at delivering photosynthetically active radiation (PAR) to the canopy in the form of usable light, which is referred to as photosynthetic photon flux density (PPFD).
Translated: LED lighting can deliver the same light intensity at a lower wattage than HID systems.
Also Read: To learn more about the importance of PAR and PPFD, read our in-depth guide on Grow Light Distance
Many growers aim for a 1-2 gram yield per watt with LED systems. Growers have achieved excellent results with 35 to 40W per square foot, roughly 350 to 400W per square meter. To find the square footage/meters of your grow space, multiply the length by the width.
How far should LED grow lights be from plants?
An LED buyers guide for cannabis wouldn’t be complete without discussing this question. Briefly, we can say LED lighting can be placed closer to the canopy than HID systems. They also provide a better light spread (even distribution). LED lights have the advantage of dimmers, which let growers control intensity without raising or lowering the light fixture.
Because variables like life stage, wattage, and photoperiod will all factor into deciding how high to hang your LED grow lights, check out our grow light distance charts. That article will provide new growers with all the information they need to make an educated decision.
How much energy will my LED lights consume?
The manufacturer will provide the light wattage in the main product description. The power drawn from the wall is often slightly higher or lower than the stated wattage. Not to worry, most LED lights’ variance in wattage is negligible. You can purchase devices measuring power drawn from an outlet/device online for under $40.
One of the important differences between LED and HID systems is the efficiency. LED systems can produce similar results using less wattage. In the formula for this equation, efficiency is represented by micromoles per joule (µmol/J), and power consumption is represented by wattage. To calculate your power bill, use a power usage calculator
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What color LED is best for plant growth?
The way humans and plants perceive light is different. Our eyes see a cumulation of all wavelengths (full spectrum) as white-colored light. Instead, the plant absorbs the individual wavelengths of light at different ratios. Color is represented by different nanometers (nm) of light wavelengths called PAR.
The spectrum(s) of light directly relates to plant growth characteristics. Blue light can keep nodal spacing tight; red light can promote flower growth. We now know that monochromatic light isn’t the best choice for plant growth. To better understand why this is, we’ve created an article detailing the role of chlorophyll in cannabis. Remember, chlorophyll is an essential component of photosynthesis.
What is CRI (color rendering index), and why is it important?
The color rendering index tells us how accurate the color we see with our eyes is, compared to the actual color. An easy example of poor CRI is when looking at plants under blue & red diode LED lighting. The low CRI is evident in the lack of natural color when looking at the plant. All of the leaves look purple!
By turning off the blue and red LED lights, we improve our CRI and get a truer idea of the leaf color; the same goes for HPS bulbs. The CRI scale ranges from 0 (poor) to 100 (true color). Most of today’s LED lights for growing cannabis are white light (full spectrum) with high CRI.
Are the quality of diodes important?
Yes. The quality of the diodes can affect color spectrum, heat signature, light dispersion, PPFD, and longevity. Growers who have researched and visited a few of the manufacturers’ websites might notice that many of the budget lights use the same model number of diode as the expensive brands use in their lights.
The gap in pricing is possible because diode manufacturers grade the quality of the diodes they produce within the same model number. Some are A-grade, others are C-grade, but they are the same model number. One diode performed better in quality control testing than the other. Instead of using a letter grade, companies like Samsung have adopted a BIN rating system.
***You can see an example of the different BIN ratings here (click “show more specs” under the Tech Specs section)
Does the quality of the build material matter?
Quality material means a product should last longer. That said, chassis for LED lighting are similar amongst most manufacturers. Many take advantage of the lightweight and heat-dissipation properties of aluminum. There are occasional differences in how LED light bars attach to the main body. Some attach within the chassis, while some companies opt for external plastic clips.
A large portion of the price difference between LED lights can be attributed to the brand of driver it uses. This piece converts power from the wall to power the LEDs. Among the budget brands, only a few widely used driver models exist. Dimmer boxes are another area where the overall price reflects a component’s quality, accuracy, and longevity.
How easy are LED lights to use and install?
Installing a new LED grow light is possible for one person. If the light doesn’t come assembled, start there. Then position the light, hang it, plug it in, and turn it on. For a step-by-step guide, check out our article – A beginner’s guide to hanging grow lights.
Some LED grow lights can connect to a dedicated app, which gives growers control over the lights from their phones via WiFi or Bluetooth. You can fully automate your light cycles if you’d like. You can also run those smart lights with a traditional timer if new technology is not your idea of fun.
Learn how to buy the right timer by reading our article, best timers for grow lights
Consider the warranty before buying!
Although many diodes are rated for 50,000+ hours of use, if one or a few go out, it’s not a part most users could replace themselves. Most components on LED lighting require soldering to replace. Repairs like this require special skills and equipment most people lack. .
LED lights are big and heavy to ship; who covers shipping costs on warranty repairs? Where is the nearest repair facility? Would warranty repairs have to be shipped internationally? How easy is the company to contact, and how quickly do they respond? Do reviews online rave or complain about warranty service? All of these factors should be considered by new growers when buying LED lights for growing marijuana.
Three main types of LEDs
Bar-style LED grow lights:
You will find most companies using bar-style lighting. Bar-style lighting involves a strip of LED lighting every 6-8”. This configuration allows for maximum airflow and heat dispersion at the light level. The spacing of the bars better distributes usable light in a consistent pattern that keeps PPFD numbers in the corners closer to those in the center. In contrast, quantum boards create a hotspot in the center and lower numbers in the corners.
Quantum board LED grow lights:
Quantum boards, also called panel-style lights, are typically a square or rectangle footprint with even rows of diodes mounted on the board. This style of lighting features full-spectrum white light and replaces the early blue and red light LED technology. This style improves efficiency, light spectrum, and heat dissipation. Quantum boards don’t require onboard fans for cooling, making them a quiet and discreet option for lighting.
Chip-on-board (COB) LED grow lights:
Chip-on-board (COB) lighting is similar to quantum boards in that it is an array of small-sized but high-powered LED chips mounted onto a singular board. The obvious difference is the compact configuration of COB lighting compared to the layout of quantum board diodes. The light spread from COB lighting is narrow compared to the options above, requiring more lights to cover an equal area. COB lighting also produces more heat, requiring a fan for cooling.
What are the guidelines for grow lights?
Hopefully, this guide has answered how growers can choose the best LED grow lights. The key things to remember are:
- How many plants do you want to grow?
- What are the dimensions of the space you are growing in?
- How much available wattage do you have on the wall?
Combine that knowledge with your budget and start shopping. Do your diligence by investigating the details of the warranty and reading reviews.
We hope this buyer’s guide about LED lights for growing cannabis has benefited new and experienced growers alike. To learn more about the entire grow journey, download Robert’s Grow Bible for all the knowledge you need for successful and bountiful harvests. After the lights are hung and the soil prepared, pick up some seeds at ILGM and begin your growing adventure.
If you run into any questions along the way, check out our blog or contact us. Is there anything we omitted from this buyer’s guide about LED lights for growing weed? Let us know in the comments below. Also, we’d love to hear your most important factor when purchasing an LED light.
We are looking forward to reading your comments. Happy growing!