The Complete LED Grow Light Guide

If you’re reading this, chances are this isn’t your first look into LED grow lights. In fact, you’ve probably already searched online for the right info, but now you have more questions than answers.

“Diodes? Chips? Targeted wavelengths? 4000k? Primary vs. supplemental lighting?” LEDs may have sounded great at first, but after so many questions, you find yourself on the verge of going with an HID or not growing at all.

LED grow lights may seem a little intimidating at first, but once you gain the knowledge about LEDs, you'll find that they can give you the same yields — if not better — compared to HIDs. That’s where this guide comes in handy.

In this guide, we’ll walk you through the ins and outs of LED grow lights to help you understand what makes them so useful in the grow room or grow tent, and how to make the best choice for your plants. From what they do to how they’re made, all the way to choosing the right setup for your grow room, this guide will be a roadmap on the way to high-quality harvests using LEDs.

1. LED Grow Lights 101

• Setting Up an LED Grow Light
• Why Grow With LEDs?
• LED Grow Lights Inside and Out

• Diodes
• Power Supply
• Housing
• Types of LEDs

• Traditional
• Spread
• COB (Chip on Board)
• Primary vs. Supplemental Lighting
• How to Choose the Right LED Grow Light for Your Plants

• Choosing the Wavelengths Your Plants Need
• Choosing the Strength Your Plants Need
• Growing With LED Grow Lights
• What the Experts Recommend
• Frequently Asked Questions

LED Grow Lights 101

 

As the name suggests, these types of grow lights use light emitting diodes (LEDs) to grow plants instead of high pressure sodium, metal halide, or fluorescent light bulbs. LEDs are electronic-based, which makes them the only type of light that doesn’t require a chemical reaction to work. This opens up a whole host of advantages over HIDs that we’ll discuss in a bit.

While LEDs vary in design and intensity, they all work essentially the same way:

1. When an LED grow light is turned on, energy in the form of electricity is given to diodes on the light.

2. The electricity runs into the diode and streams across it a computer chip, which creates electromagnetic radiation.

• Note: The size (wattage) of the chip will determine how bright a diode will be, and the number of diodes on a light will determine the grow light's overall strength.

• The radiation created in this process results in visible light, which we can see with our eyes and, most importantly, can be utilized by plants.

The radiation generated by LEDs naturally is a piercing blue. A phosphor coating is added over the chip to defuse it so it’s not hyper intense, which would harm the chlorophyll in a plant. Chip dye can be added to each diode to give off particular photons (colors) of light outside of the white/yellow/orange light we’re used to seeing. The strength of each chip, the photons they emit, and the number of diodes in a grow light all come together to give you an LED.

Setting Up an LED Grow Light

Interestingly enough, LED grow lights offer a few assembly and setup options. Most LEDs don’t require you to put anything together, unlike HIDs that require you to assemble a reflector, ballast, and bulb. For the most part, they’re straightforward:

1. Install the light hangers onto the LED light/panel.

2. Hang the lights above your plants.

3. Plug in your lights to their power outlets and turn on the lights.

Now, there are lights like those from Horticulture Lighting Group that require some assembly. Though it’s not difficult, you’ll receive a mounting board, a driver, and a number of LED panels to install. In these cases, here’s what you’d do: 

1. Lay out the mounting board and lay out each panel where they belong on the board.

2. Fasten the panels to the mounting board. Some use screws, while others may use an adhesive, so adhere the diodes to the board as instructed.

3. Install the driver (a ballast for LEDs) where instructed, usually on the back of the mounting board.

4. Wire the diode panels into the driver.

5. Install your mounting hardware and hang your LED grow light over your plants, then plug your light in and turn it on.

There are also certain lower wattage LEDs bulbs that you can install into flood lights, too. Those are as simple as screwing the LED bulb into the flood lamp, plugging in the lamp, and turning it on.

Keep installation and assembly in mind when choosing the right LED grow light for your plants. If you have the tools and the time, you could save a few extra bucks buying one that requires assembly. Otherwise there’s no problem simply hanging your light and turning it on, no assembly required.

Why Grow With LEDs?

LED grow lights have gone through a number of improvements to get to where they are today, so it makes sense that many growers are wary of them. On the flip-side, HIDs have been around much longer than LEDs and have become a tried and true way to grow indoors. In the end, though, LED grow lights have proven their efficiency and effectiveness in the grow room. Here's why: 

• Low Heat Generation — LED grow lights are the only lights around that don’t need to heat up metal or gases to extreme temperatures, unlike HIDs. That energy and the heat created by it are why HIDs get so hot and end up adding heat to your grow room. The heat from the radiation that LEDs emit is minimal — nowhere near the heat generated by HID lights. This heat is more of a nice addition to your garden compared to an HID's heat, which can create stressful, overheated conditions for your plants if not regulated.

• Low Energy Consumption — LEDs use much less energy to run than HIDs. Consider the S720 Advance Spectrum MAX LED Grow Light Panel that consumes around 465w of power but has almost the same intensity as a 1000w HID. This LED gives you the same amount of PPFD as an HID twice its wattage, and you won’t need to regulate its heat. Cooling and ventilation equipment will need to work less with LEDs, which will reduce your energy consumption even further.

• Pinpointing Vital Wavelengths Plants Need — LED grow lights are great at giving plants the specific wavelengths of light beneficial to growth. Plants only absorb certain wavelengths of light, so the drawback to HIDs and T5s is that plants waste a lot of the light their broad spectrums provide. LEDs have the ability to pinpoint and increase the availability of various blue and red wavelengths — even infrared and ultraviolet wavelengths — your plants need so they get as many usable wavelengths as possible.

• There are LEDs that offer you all white spectrums of light just like CMH grow lights, as well as warm and cool spectrums like HIDs and T5s. No matter what style of light you’re used to or want to try, you’ll be able to find an LED grow light with the spectrums of light you need to get your plants where you want them to be.

• Depending on the type of LED you have, you even have the ability to control the wavelengths of light you give your plants. KIND and MINT LEDs, for example, allow you to control the number of colored and white diodes your light gives off. That sort of customization is impossible with HIDs.

LED Grow Lights Inside and Out

While LED grow lights (electronic) may operate in a different way than HIDs (chemical), they're essentially made with the same parts. You have the diode that emits light like a bulb, a driver that transfers energy to your diodes like a ballast, and the housing of your LED which acts more or less like a reflector.

With that in mind, let’s break down the major components of a grow light: diodes, power supply, and housing.

Diodes

A diode is what’s used to translate electricity to visible light in an LED. While a diode itself contains lots of different parts (like wires, heat sinks, and bases), we’ll focus on the main components in the diode: the chip and the lens.

Chips

Chips are the surfaces that electricity runs across to give us light. The brightness of a diode is based on the strength and number of chips inside, and each of those chips has a wattage it takes to give off light. 

Most LEDs use .5w, 1w, 3w, and 5w chips that offer you a certain amount of lumens. The more lumens a chip can give off, the brighter the diode will be. The more diodes you have, the stronger the overall LED grow light will be. And the more lumens a light has, the better it will be at penetrating your plants' canopy for vigorous growth.

It should be noted that the more chips you have on a diode’s surface, the higher the lumen output will be out of a diode. For example, COB chips work by using a lot of little, low wattage chips (around .25 to .5w) on a relatively small surface. All of these tiny chips come together to give you a super bright light, even with a phosphor cover.

Dying and Covering Chips — Chips are usually (but not always) dyed to give off a certain color that mimics a particular wavelength of light along the light spectrum. Non-programmable diodes are dyed the color they should be, whereas diodes in adjustable LEDs are dyed blue, red, and green. The particular color combination will allow you to get white, blue, red, green, and violet wavelengths that plants need.

Whether they're dyed or not, a small phosphor cover is placed on the chips to dampen the piercing light that electricity gives off from the chip. In the case of ultraviolet diodes, the chip cover is made of crystals like sapphire to offer that intense wavelength when light radiation is offered. Infrared diodes, on the other hand, have secondary internal reflectors that filter light coming out so that only IR wavelengths of light are emitted.

Lens

The lens covering each diode helps focus the light coming from each chip so that it doesn’t emit into the open air unfocused and ineffective. This lens is what facilitates the intensity of the light given off by the chip. Therefore, the type of lens a diode has will help determine how the light is focused down onto your plants.

Contrary to popular belief, the beam angle (or the width of the beam of light coming out) doesn’t depend solely on the type of lens used. Rather, it comes from how close a chip is to the lens. The further a chip is from the lens, the more narrow and intense the light will be coming from the diode. The closer the chip is to the lens, the wider and softer the beam of light will be. Here’s what this idea looks like in real life:

 

• 180° beam angles are achieved with simple protective covers over chips. The spread on these lights is wide, giving you a big lighting area that can cover lots of plants. Though that wide coverage area isn’t filled with intense PPFD, getting more intensity you’ll only requires more chips and/or higher wattage chips. That’s why spread-style LEDs are the most common lights that offer 180° angles, as they contain hundreds of smaller low wattage chips that cover wide canopies with soft but effective light.

• 90° beam angles start out with thick, domed lenses. The chip of a 90° beam is raised close to the dome of the lens to offer a wide but intense beam of light down onto your plants. These are traditionally used on COBs and traditional lights because of their ability to spread light while focusing lots of it down onto plants for intense growth.

• 60° beam angles come from the same thick lenses, only this time the chip sits around halfway between the chip and the top of the lens. This beam of light is more narrow, and while it does offer much more intensity for your plants than 180° and 90° beams, it also offers less coverage area. If you’ve ever seen an LED that touts extreme intensity, chances are the light produces 60° beam angles or offers a dual lens.

• Dual lens diodes contain two lenses: the primary lens, which gives your plants an initial 90° beam angle, and the secondary lens, which takes that 90° beam and intensifies it by focusing it into a 60° beam. This intensity helps canopy penetration from far distances.

Diode Arrangement

Diodes on an LED grow light are arranged in certain combinations to ensure it works properly depending on the drivers used. There are two types of arrangements: panels and diode clusters. 

• An LED panel consists of diodes (usually with 180° beams) wired together and mounted directly to a panel, all illuminating when activated. Supplemental lights are a single panel of low-wattage chips mounted to a surface, whereas standalone lights consist of multiple panels outfitted with a number of 3w chips each. Usually in these arrangements, if one diode goes out, the entire panel will go out.

• Diode clusters arrange diodes (usually with 90° and/or 60° beams) in a circular or rectangular shape and place them around the light. These are mostly used in standalone lights because you can fit a number of high-powered diodes into these clusters, and a number of these clusters in a grow light. However, you can find these clusters used in supplemental lights, and each cluster gets its own power supply.

A Quick Note on Bleaching and Leaf Burn 

While LED grow lights may not produce heat, the light they do produce is intense. Remember that the light coming from LEDs is the result of electricity, and raw electricity is extremely bright, which is why it needs to be buffered by a cover and lens.

The problem with LEDs is that regardless of how much you dampen chips, the light produced is still super intense. As such, lights that are too close to plants can actually bleach them. When this happens, light damages the chlorophyll in the leaves, flowers, and fruit your plant produces. When chlorophyll is destroyed, plants have a hard time taking in light and breaking it down to use as energy. The plant will usually continue to grow, but it will be weaker, and the color you love on your plants will definitely be tarnished.

We should also mention that while the heat produced by LEDs is very minimal, the electric radiation they create produces heat. Thankfully, lenses and covers help insulate some of that heat, but when plants press up against diodes that’ve been on for hours, there’s a chance the diodes can get extremely hot and start to burn a plant. Some burns can be simple discoloration and damage, while sustained burning can lead to combustion if not mediated.

Fortunately, bleaching and burning are remedied simply by hanging your plants at the right height, which is anywhere between 18in and 30in above plants. That’s why it’s imperative to choose the right LED for your grow room. You don’t want something that’s so strong you have to hang it at a height that won’t help your plant. At the same time, you don’t want something that’s so weak you have to hang it close to your plants and risk bleaching or burning them.

Power Supply

The power supply, or driver, of all LED grow lights is essentially the brains. The driver is what helps regulate the voltage coming into the light so that it doesn’t overpower each diode and cause shorts. It's also responsible for protecting LEDs from power fluctuations that can cause your light to short. 

The driver controls the amount of energy each chip gets, so aside from consistent running, drivers are also responsible for regulating the intensity and use of chips. Especially in the case of lights with programmable light, drivers have the ability to turn on and off particular colored diodes, as well as the intensity given to each diode.

The type of driver used depends on how much power it needs to regulate. There are internal and external drivers that help various types of grow lights depending on the strength of the chips it will need to power. 

• Internal drivers are small but capable of powering a good amount of chips. They’re commonly used for lower wattage grow light panels like the 50 Watt Advance Spectrum Dual Band LED Grow Light Panel that have one hundred .5w chips, but can be found in higher wattage lights like 100w COBs with one 100w diode.

• External drivers are capable of powering many more chips at much higher wattages. For example, each diode cluster in the S180 Advance Spectrum MAX LED Grow Light Kit requires its own external driver. That’s because each cluster contains fifteen diodes with 3w chips, including UV and IR that require a special considerations. Large panels like those from Black Dog LEDs need to power hundreds of 3w and 5w chips across a number of panels, so they also use external drivers.

• Because external drivers take in and distribute so much energy, they have built-in heat syncs and even power fans to keep cool.

Housing

LED grow lights don’t use traditional reflectors like HID and T5 grow lights do. For the most part, they don’t use reflectors at all. Instead, each driver, diode cluster, and panel is housed in a shell. The shell offers openings for the diodes and chips to emit light from, while offering a white or silver reflective background to help reflect the light each diode emits down onto your plants. 

There are benefits and challenges to using LED grow lights with shells:

• If you have a more complicated light — say, a dimmable LED grow light with lots of diode clusters that have their own drivers — shells will help keep all that technology safe from dust and moisture found in the open air. They’re also made with air vents to help air flow to prevent overheating.

• LED grow lights without shells, from supplemental lights to high-powered ones, tend to be more minimal in design. When working with these lights, make sure to keep an eye on the moisture and dust around the light. They’ll work as well as lights with a shell, but keep in mind that they're more exposed to the environment.

You shouldn’t be swayed one way or another about a light based on whether it has a shell. Ensuring drivers are able to safely operate and give your diodes energy is just as important, and that will depend on whether your light has a shell or how clean you keep the area around drivers and diodes.

Types of LEDs

Now that you know what LED grow lights are made of, let’s talk about the types of LEDs that are out there for you. There are a lot of styles with their benefits and challenges, so let’s dive into the types of LEDs you can choose from.

Traditional

Traditional LED grow lights are an industry standard these days. They’re some of the most reliable LEDs on the market, with individual drivers controlling up to 100w per cluster.

Out of all LEDs, traditional lights have the most versatility. Each diode in a traditional LED has 1 to 5w chips depending on the strength of the overall light, with 1 to 2 lenses helping project light. A single lens will a light to give you a 90° focus beam of light, and a secondary lens would give you an extra 60° of focus to intensify that further.

These lights also have the widest spectrum availability. From cool and warm temperatures like T5s to deep purples all the way to UV and IR lighting, there’s virtually no wavelength of light that traditional LEDs can’t give you. 

As great as they are, traditional LEDs can be on the heavy side. The stronger the light, the more equipment is used, which adds weight to the light. Any light falling on your plants will harm them, but a high-powered traditional LED like the S900 Advance Spectrum MAX LED Grow Light Panel that weighs over 30 lbs crashing down onto your plants will annihilate them, no question.

So when you’re going the traditional route, focus on two things: ensuring it has the spectrums of light your plants need, and that your grow room is equipped to handle at least 25 to 30 lbs securely.

Spread

Spread-style LED grow lights get their name from the way the diodes on them are spread across their surface. They’re relatively inexpensive compared to other LED grow lights, and just as effective despite their limited wavelength offerings.

The chips in spread-style LEDs tend to be low, but with the number of diodes on each panel, the possibilities of reaching a high lumen output are virtually endless. That’s because of two key structural factors:

1. Each diode contains a single .25 to 1w chip. With an average lumen output of 60 lumens per watt, a simple 50w panel with 50 chips can give you 3000 lumens of light — that’s more intense than a 54w T5 6400k bulb. 

2. Spread LEDs usually don’t use domed lenses. This frees up space on each panel to fill with as many diodes as possible. This will both increase the overall intensity of the LED and increase the light footprint it casts.

While they have the possibility for wide, even light coverage, that coverage tends to be less focused than with other LEDs. This results in softer coverage, requiring many more diodes to increase power. When using spread LEDs, be sure you have plenty of room to adjust their height as needed. If you don’t have the room to raise your lights, make sure the spread LED you choose offers a dimming feature.

COB (Chip on Board)

COB stands for “chip on board”, and it’s called that because of the construction of the diodes. Each diode contains many tiny, low-wattage chips that shine together to give you a super charged light out of a single diode.

50w COB diodes, for example, usually have fifty mini 1w chips on one small surface, giving you around anywhere from 3000 to 5000 lumens out of a one diode. That’s right — the same intensity you’d get out of a fifty 1w chips on a larger panel, you can get out of one COB diode. It will take fewer COB diodes to give you the same lumens as a spread or traditional panel, which means you can get high-powered COBs in much smaller sizes than other LED grow lights.

While they offer crazy intensity, the issue with COBs lies within their limited spectrum availability. These are available primarily warm 3500k spectrums and cool 6000k spectrums, but nothing in the way of multi-colored wavelengths, IR, or UV spectrums. However, if you’re looking for a grow light with huge intensity out of a small light, COBs are the way to go.

Primary vs. Supplemental Lighting

Like the names imply, LED grow lights can either be your plants primary source of light, or they can be used to supplement the lights you’re already using. 

Your primary lights will have the most significant impact on your plants. Therefore, you’ll want to ensure these lights offer plenty of strength to stimulate plant growth. 

• At the lower end of the scale you’ll see 210w LED grow lights that offer peak PPFD at 455 or higher, which is good for a single flowering/fruiting plant. 

• On the higher end, you have 1000w lights that pump out over 1700 PPFD, which is more than enough for 2 to 3 mature fruiting plants per light.

As far as their spectral availability, primary lights come with an array of multi-colored spectrums, as well as white color temperatures. Some primary lights offer 1 spectrum, while other lights have the ability to adjust spectrums. The Kind LED K5 Series XL750, for example, has programmable wavelengths to offer plants all-red, all-blue, all-white, or a mix of wavelengths depending on the stage of growth. No matter what spectrum of light you give your plants, make sure your primary light has all the wavelengths they need.

Supplemental lights, on the other hand, are made to supplement your primary lighting. You can use them to fill in dark areas around your grow room when your primary lights can’t reach. They're also perfect for seedlings, clones, and young plants because they give them enough light to grow without overwhelming them. 

For example, the 50 Watt Advance Spectrum All Blue LED Grow Light Panel has over 100 low-wattage chips. These will help fill in gaps of light around your plants during the vegging stage, and can give you enough light for smaller plants like clones and seedlings.

In general, supplemental LEDs are great at giving your plants an additional amount of lumens and wavelengths they need. If your primary light can’t give your plants all the lumens or wavelengths they need, using one or more lower-powered supplemental LED grow lights will help your plants get all the light they need to thrive.

Some supplemental lights have multi-colored diodes, others come with white color temperatures. The most popular supplemental lights come in a single targeted wavelength, usually all-blue or all-red.

How to Choose the Right LED Grow Light for Your Plants

The LED you choose will be a vital part of your garden’s success, so it’s important to choose the right one. Despite all the knowledge you have about LED grow lights now, it can still be tricky to find the right one for you. So let’s look at the features you should pay attention to when shopping for the best LED for your grow room or grow tent.

Choosing the Wavelengths Your Plants Need

Particular wavelengths of light along the light spectrum stimulate specific functions within the plant. For example, red wavelengths help stimulate flower and bud growth, and blue wavelengths help stimulate branch and leaf growth. 

Some LED grow lights target specific wavelengths of light — like 660nm red or 465nm blue — by dying their chips a specific color. Other chips are covered and offer spectrums of light like 3500k or 5000k that give you a wide range of wavelengths depending on the phosphor used. Both are beneficial for your plants, so how are you supposed to know which ones to go with?

In order to know what to choose, it’s important to know what your plants need. Here are the wavelengths your plants will need:

• 430 to 450 nm blue wavelengths are necessary for root growth.

• 640 to 680 nm red wavelengths are necessary for stem growth, as well as chlorophyll, flower, and bud production.

• IR (710 nm) helps stimulate resin production.

• UV (10000k) helps strengthen stems and create stronger plants.

• Note: The “K” here stands for Kelvin, which is a measurement of color temperature. The color temperature of a light is a reflection of the color given off by that light, which is usually a form of white light that contain a wide range of wavelengths.

COB and spread LED grow lights often use white light that falls within 3500k and 5000k color temperatures. These two temperatures contain all of the wavelengths of light your plants need, with 3500k offering a little more red wavelengths and 5000k offer more blue. 

Lights with these wide spectrums are great for growers used to HPS and MH grow lights who want the same spectral range. While it’s true plants will waste a number of the wavelengths they receive with these color temperatures, they won’t fight excess heat doing so like with HIDs. In this instance, having more spectrums than necessary can be a good thing.

Traditional LED grow lights tend to use what’s known as targeted lighting. Instead of offering huge spectrum ranges, these lights target specific nanometers (nm) of light your plants need instead of giving them with a wide range of wavelengths. These offer designated blue and red wavelengths, along with a range of orange, light blue, and even IR and UV wavelengths for a bump of protection and flavor.

These lights are capable of growing extra strong, healthy plants, as they target wavelengths plants need to ensure they don’t waste any energy getting rid of light. Because they’re so targeted, though, it’s important to make sure the wavelengths fall within the ranges above. Without them, your plants are going to struggle to grow.

Now, of course, wavelengths of light are only as helpful as the diodes that emit them. After you figure out which wavelengths of light you want to work with, it’s time to figure out the strength you’ll need for your grow room.

Choosing the Strength Your Plants Need

The strength of an LED grow light is going to determine how effectively your plants grow. If your grow light’s too strong for your plants, you’ll end up bleaching and burning them. Too weak of a light and your plants will grow underdeveloped, stretched out, and they’ll be unable to support themselves. 

In order to figure out how strong of a light you need, you’ll first want to find out what the amount of usable light — i.e., PPFD, measured in micromoles (µmol) — your plants need. According to experts, most plants thrive off 65µmol (PPFD) per sqft, so it’s our job as growers to make sure our plants get the proper amount of light they need to thrive.

It’s important to remember that when we’re talking about lighting requirements, we’re speaking about lighting the canopy. A garden’s canopy is the leaves and growth that need to be lit, not the entire growing area. Keep this in mind because if you get a light for your entire growing space instead of the canopy, you risk getting a light that’s too strong for your plants. Moreover, note that all plants are different and will require research as to their specific recommended PPFD.

Calculating the PPFD Your Plants Need

To calculate the PPFD your plants need, here’s what you’ll want to do:

1. Measure the length, width, and height of your canopy. Remember: The canopy is only the area you plan on lighting — it should only be the amount of greenery you plan to cover in light. For example, if you lollipop your plants, the height wouldn’t be the entire length of the plant. Rather, it will be just the leaves, flowers, buds, and fruit you want to light, which is usually the top 6 to 10 inches of the plant.

2. Take the recommended amount of µmol your plants need and multiply it by the volume of your canopy.

• Though recommendations for plants are measured in sqft, it’s important to also account for light penetration. This can be done by also adding in the height of your plants.

Let’s put this into action. Say that your garden’s canopy measures 3ft x 3ft x 10in (we’ll round that up to 1ft), and your plants need 65µmol/sqft.

1. 3 x 3 x 1 = 9cu ft to cover

2. 9 x 65µmol = 585µmol (PPFD) required for your plants

Once you have the PPFD your grow room needs, it’s time to find the light that can meet it. To do that, make sure the LED grow light you’re looking into has PPFD charts to show its PAR ratings and intensity at different heights. From there, keep a few things in mind:

• If you have a big canopy that requires lots of PPFD, it’s better to use multiple lower-watt lights instead of one powerful light. This will give you more even light coverage across your canopy, resulting in more uniform harvests (i.e., the same size buds/fruits/flowers). 

• The shape of the light will play a big part into its footprint, and subsequently its effectiveness on your grow. The wider/narrower a light is, the wider/narrower its footprint will be. Rectangular LEDs, for example, have great intense coverage horizontally but have weaker coverage vertically. Square LEDs, on the other hand, have a more even footprint. 

  

• Make sure you have the space to fit the LED grow light you need in your growing area. For example, if you need a light that measures 2ft x 3ft, be sure your grow tent or growing area is at least 4ft x 4ft to be sure you have plenty of room for your plants and grow light.

• Diode layout and type are different from light to light. Three LEDs can offer you a peak PPFD of 1000 µmol, but depending on the number and type of diodes used in the LED, the light will be different.

• A single COB can be up to 100w, which means you’ll need only a few of these diodes on a light for high intensity. However, that means the light will be relatively small, giving you a smaller footprint than others.

• Traditional LEDs are equipped with a number of 1 to 3w diodes and 90° and/or 60° lenses to keep up with larger wattage lights. To match one 100w light, a traditional light would need anywhere between 30 to 50 diodes with 2w or 3w chips. This will give you a rectangular footprint with intense coverage in the center of the canopy, though it will become weaker on the outsides.

• Spread LEDs usually have lots of diodes with .25 to .5w chips on a surface. To reach 100w, for example, you’d need at least 200 to 400 diodes. This results in physically larger lights than lights with stronger chips, which actually benefits your plants. Though the light they give off is not super intense across the board, it’s much more even than other LEDs.

Growing with LED Grow Lights

So there you have it, folks! From the construction down to the very diode, you’ve learned everything there is to know about LED grow lights and what to look for when shopping for one. Now you’re ready to make the best, most well-informed decision for your grow.

If it were only that simple, right?

Let’s face it: We can get all the information we need and do all the research possible down to finding the manufacturer of each chip in every diode. The truth is even with all that info, it’s much easier to know what to look for when you have a little help. That’s why we turned to the experts to see what LED grow light brands are the best fit for your grow room.

What the Experts Recommend

When it comes to the best LED lighting, we went to expert LED growers for their recommendations. From fruits and veggies to medicinal plants and flowers, we went on a mission to find you the best brands for the plants you want to grow. Here are the top five LED grow light brands we saw pumping out big, consistent harvests.

 

Best LED Grow Lights Overall: Advance Spectrum

We don’t say Advance Spectrum is the best overall brand simply because of these LEDs' intensity (which comes in spades). Advance Spectrum LEDs range from softer 24w supplemental LEDs all the way to intense primary lights of over 720w, all with varying strength diodes tailored to fit any growing style.

The lower-watt (24 to 50w) supplemental lights are spread-style with internal drivers and .5w chips, giving young plants soft light to absorb. Meanwhile, the larger-watt Advance Spectrum MAX line of primary LED grow light kits have external drivers, 3w chips in each diode, and even offer IR and UV diodes to boost resin growth and plant strength. 

 

In addition, Advance Spectrum also has the widest selection of lights on this list, with a standard Advance Spectrum line of lights that range from 25w to 50w, in single and multi-colored chips. The high-powered Advance Spectrum MAX line from 180w (455 PPFD) to 900w (over 1000 PPFD) are all targeted, highly intense full spectrum lights. So if you’re looking for a brand that has everything your plants need, as well as costs that go easy on your wallet, Advance Spectrum LED grow lights are what you’re looking for.

• The 24w LED lights are great for 1 tray of clones or seedlings, as well as small herbs and spices.

• The 50w LED lights work great for 1 to 2 trays of clones and seedlings, as well as herbs and spices.

• The S180 LED Grow Light Kit and S270 LED Grow Light Kit are perfect for 1 to 2 mature flowering plants, along with a host of leafy greens and vegetables.

• The S360 LED Grow Light Kit and S450 LED Grow Light Panel can grow 2 to 4 mature flowering plants, as well as a number of vegetables, including root veggies.

• The S540 LED Grow Light Panel and S720 LED Grow Light Panel work great with 3 to 5 mature flowering and fruit bearing plants.

• The S810 LED Grow Light Panel and S900 LED Grow Light Panel are the perfect lights for 5 to 7 mature flowering and fruit bearing plants.

Best LED Grow Lights with UVB: California Light Works

California Light Works is known for its wide range of personal and commercial LED grow lights, but the company's standout lights have to be the SolarSystem UVB lights. While UVB diodes may be helpful during growth, their effect is minimal compared to a dedicated bulb. Complete with two 24w UVB bulbs per light, the SolarSystem 550 and 1100 systems give your plants the best, most efficient amount of UVB of any grow lights on this list. 

That’s not even mentioning the strength that these lights already offer on their own. These spread-style LED grow lights have high-efficiency OSRAM diodes and offer three programmable spectrums (veg, bloom, and full spectrum). You can even fine-tune wavelengths of light with the included controller for a light crafted just for your plant. On top of that, their diodes kick out some serious power for commercial and at-home grows.

• The SolarSystem 550 gives you 888 PPFD with a 4ft x 4ft footprint during flowering and a 6ft x 6ft footprint during flowering. That’s enough for at least 2 mature flowering plants per light.

• The SolarSystem 1100 gives plants 1730 PPFD with a 5ft x 5ft flowering footprint and an 8ft x 8ft vegging footprint. That’s enough room and intensity to cover 4 to 5 mature flowering plants.

• Each UVB bulb used on these grow lights gives off 90 PPFD at 36in to plants with a 4ft x 4ft footprint. Now double that energy and lower it at 6 to 18in lower, and that UVB intensity skyrockets!

While it’s true that too much UV will harm a plant, the T5 fluorescent bulbs included with these lights is softened by phosphor. This helps buffer your plant from too much UV that will harm it, giving your plants only beneficial wavelengths. So when you’re looking for a light that gives you huge amounts of UVB instead of the steady amount given by diodes, California Light Works will give your plants exactly what they need.

Strongest LED Grow Light: Black Dog LED

If you have extra large plants or need to cover large areas with super intense light, Black Dog LEDs are what you’re looking for. From warehouses to closets, these LEDs offer 2 to 5w chips in each diode, giving these relatively small grow lights huge intensity and wide footprints.

 

Take the Black Dog LED PhytoMAX-2 200 LED Grow Light, for example. This light offers a 3ft x 3ft footprint at 21in above plants with 330 PPFD at 210w of power. At 16in above plants, that number jumps up to 587 PPFD, which is more than enough light for 1 to 2 plants to thrive in a 3ft x 3ft coverage area. Even a step up with the PhytoMAX-2 400 packs a huge punch, giving you 660 PPFD at 21in above plants. From there, the intensity levels go up even further, as explained below.

• The PhytoMAX-2 200 will give you 330 PPFD at 21in above plants, which is enough for a single flowering plant to thrive off.

• The PhytoMAX-2 400 offers 660 PPFD at 21in above plants, which will give you enough strength to grow at least 2 to 3 flowering plants in a 4ft x 4ft area.

• The PhytoMAX-2 800 gives your plants a whopping 971 PPFD at 25in above plants. That’s enough strength to grow 3 to 5 mature flowering plants in a 6ft x 6ft growing area.

• The PhytoMAX-2 1000 gives you an insane 930 PPFD at 29in above plants (so you can imagine the huge jump in strength lowering that down to 25in). This is enough to cover at least 4 to 5 plants in a 6.5ft x 6.5ft area.

Whether you want a couple of super-charged plants or you want to cover a large number of plants across a large area with a single light, all you need is a few Black Dog LEDs to crank out all the light you need.

Best Programmable LED Grow Lights: KIND LED

Can’t choose between targeted lighting and all white lights? With KIND LED grow lights you won’t have to. With 3w and 5w chips projected by 60° lenses, their K5 Series of grow lights are some of the best programmable, traditional LEDs on the market. You’re able to give your plants a whole host of spectrum and lighting schedule options from your laptop or tablet for remote-less control over your grow light. 

• Program your plants to receive blue variants of light to help root growth and branch growth; red variants of light to help boost leaf, branch, and flower growth; or white light in case you want to give your plants a wide spread of wavelengths.

• You can also program all three spectrums to give your plants a traditional spectrum of light that’s targeted, intense, and effective.

• Each K5 LED grow light also comes equipped with UV and IR diodes, so in addition to getting as many or as few wavelengths as you need, your plants get a boost of resin growth and strengthening of branches.

• The K5 XL750 LED Grow Light offers your plants 458 PPFD at 36in above plants, which works perfectly for 1 to 3 flowering plants.

• The K5 XL1000 LED Grow Light gives you 720.25 PPFD at 36in above plants,which is more than enough light for 3 to 4 flower plants.

For growers without a computerized way to program your light, you can always use the onboard system to program both the spectrums you want to give your plants and the intensity. And programmables aren’t the only type of lights KIND LED offers, either. They’ve got spread and various other traditional, target LED grow lights for any grower in any grow room, grow tent, closet, or warehouse.

When you can’t decide what spectrums work best for your plants, go with the K5 series of lights from KIND LED. You can give them as many or as few as you want, and lower and raise the intensity to match your plants' needs down to the lumen.

Best LED Grow Lights for Beginners: Horticulture Lighting Group

From growers transitioning to LEDs from HID grow lights, to growers starting their first grow, a Horticulture Lighting Group LED will give your plants the same great wavelengths tried-and-true HIDs give you, only with a softer (and gentler) light footprint.

The Samsung chips in each diode on these spread-style LEDs are .2w, and the more strength you need out of a light, the more diodes are added. Not only do these diodes come together to create an intense light, the coverage is more even than traditional and COB LEDs. With these lights, the outside parts of your canopy will be lit almost as well as the center of the light, compared to other lights where PAR drops dramatically the further you go out from the center of the light. 

• The Horticulture Lighting Group 650R has a total of 2592x 5000k (white) and 660nm (deep red) diodes, and puts out 1770 PPFD at 22in above plants with a 5ft x 5ft to 7ft x 7ft footprint. That’s enough light for 5 to 7 mature flowering plants.

• The Horticulture Lighting Group 600 series lights come with 1152x 5000k (white) diodes, along with red and blue diodes. The 600 R Spec also comes with 660nm (deep red) diodes and gives off 1522 PPFD at 22in above plants with a 5ft x 5ft footprint. The 600 B Spec comes with additional 470nm (deep red) diodes and offers 1446 PPFD at 22in above plants with a 6ft x 6ft footprint. These are great for 4 to 5 mature flowering plants.

• The Horticulture Lighting Group 550 V2 comes in an all-white version and one with an extra-blue spectrum. The ECO (all-white) LED Grow Light has 1296x 3000k diodes and gives off over 1200 PPFD at 22in above plants. The B Spec comes with 1088x 5000k and 470nm (blue) diodes, giving off 1175 PPFD at 22in above plants. These both offer a footprint of around 4ft x 5ft which is great for around 3 to 4 plants.

• The Horticulture Lighting Group 300L lights come with 576x 5000k diodes, along with red and blue diodes. The 300L B Spec offers 470nm (blue) diodes and 675 PPFD at 22in above plants, whereas the R Spec has 660nm (red) diodes and 700 PPFD at 22in above plants. These will give off a footprint between 2.5ft x 2.5ft and 3ft x 3ft, which is great for a single mature flowering plant.

Whether you’re switching from HIDs or starting off with an LED grow light, you don’t have to worry about frying your plants. Horticulture Lighting Group's LEDs will give your plants all the light they need to thrive.

Honorable Mention: Mint LED

MINT LED grow lights are simple, effective, and perfect for growing areas as small as 2ft x 2ft and up to 5ft x 5ft. 

• MINT LED 400 LED Panels have 108 diodes with 2w chips and 90° lenses that give you about 12500 lumens of light with a 2.5ft x 2.5ft footprint, enough for 1 to 2 flowering plants.

• MINT LED 600 LED Panels have 210 diodes with 2w chips and 90° lenses that give your plants 17500 lumens of light and a 3ft x 3ft footprint of light. That’s enough light to grow up to 3 flowering plants.

• MINT LED 1000 LED Panels have 210 diodes with 2w chips and 90° lenses that give your plants 22500 lumens of light with a 4ft x 4ft footprint, enough for up to 4 flowering plants.

• MINT LED 1000 COB LED Panels have 8x powerful 3000K COB diodes and 96x 6500k and targeted diodes. This gives you about 22500 lumens with a 4ft x 4ft footprint, as well. However, with the implementation of a UV bulb and IR chips, these also give you added boosts of strength and flavor to your yields.

• Note: The spectrums on this light cannot be adjusted. However, you can still adjust the intensity.

MINT LED grow lights can pack quite a punch for small and medium growing areas. If it’s a little too much for your plants while they’re young, you can use the remote (which comes with all MINT LEDs) to dim the intensity of the light at the beginning of growth, increasing it slowly over time.

You can also control one of three spectrum settings: growth, blooming, and full spectrum. Better still, its built-in timer is adjustable not only across the entire light, but per spectrum. That gives you an amount of control lights twice their price (and size) can’t offer, all from one remote — no extra timers or dimmers necessary.

When you need a compact, intense, but adjustable LED for a small closet up to a medium-sized grow tent, a MINT LED grow light will get the job done with ease.

Frequently Asked Questions

1. What wattage LED should I use?

This is a great place to start because to know what wattage (i.e., size) LED you need, you’ll want to first find out the PPFD your plants need. For example, expert growers note that plants need the following amounts of light at each stage of growth: 

• 200 to 400 PPFD is needed for clones, seedlings, sprouts, and young plants.

• 400 to 600 PPFD is needed during the vegging stage for foliage growth.

• 600 to 900 PPFD is needed for flower and fruit growth, as well as plant strengthening.

The wattage of a grow light is a reflection of how much power it takes for it to give you the light your plants need. So once you have the PPFD you want for your plants, you’ll need to find the light that can provide that much intensity. When looking for LEDs, make sure you can look up its PPFD ratings, usually through a PAR chart or even noted in the product description.

Now, not all lights are going to have PPFD ratings available. A lumen rating — like in the case of MINT LEDs — will also suffice, as plants thrive around 3000 to 4000 lumens per sqft. Of course, if that’s not available either, here are a few good rules of thumb when it comes to LED lighting:

• 13 to 75w lights are usually supplemental, great at raising young seedlings and clones or filling in gaps of light primary lights can’t.

• 100 to 250w lights are going to be on the lower end of the primary light scale, good for about 1 mature plant.

• 275 to 500w lights are in the mid-section of lights, great for about 2 to 4 mature flowering plants.

• 700w+ lights are on the high-end of lights, giving you enough light for at least 5 or more plants.

2. How much should I spend on an LED?

The money you’ll spend on an LED grow light should be a reflection of how much it costs to give you the light you need. There are a number of factors that go into the price of an LED, but here are three key aspects to look out for when pricing out your grow lights:

Features — You hear alot about IR diodes, UV bulbs, 5w chips, dimming, adjustable spectrums — all the bells and whistles a light can come with. However, all those features are going to add up. Ask yourself if it’s important or even necessary to do things like dim lights, or if you need UV and IR spectrums to pull off the harvest you want.

Keep in mind what features you need out of a light, what features you want but don’t necessarily need, and features that won’t serve you at all. Just because a light pulls out all the stops doesn’t mean it’s the right one for you.

Intensity — Not all diodes are the same. Depending on the type and intensity of diodes used, you could be spending more than you need to. For example, a COB LED will give you the same light as a spread but with fewer diodes. However, COB chips are more expensive than the .25 to .5w chip diodes spreads use, and they have a weaker footprint at higher levels. Either will work, but the key is to make sure to get a light that gives you the intensity and coverage you want at a price that makes sense for you. 

 

Construction — For the most part, the old adage is true: You get what you pay for. If you want a slimmed down LED with the bare basics, you’re going to pay less at checkout. Horticulture Lighting Group LEDs are open to the elements, require more assembly than others, and thus cost less than other LEDs. However, that doesn’t mean you’re getting the same amount of protection and longevity as you would with a better-protected light. You may have to do more maintenance (i.e., keep drivers cool and clean) to keep it running for a long time.

Advance Spectrum, MINT, Black Dog, and KIND LED grow lights all have shells and, while they cost more, tend to last longer than simpler lights. While they all may be capable of giving you the power you need, you may not get the same protection and longevity with an Horticulture Lighting Group as you would otherwise. 

3. How much electricity will LED grow lights use?

Chances are one of the biggest reasons you’re here is because you heard LED grow lights will save you money on electricity — and it’s true. LED grow lights run significantly cooler than HIDs, which not only draw a lot of power, but also require cooling equipment that draws even more energy. In comparison, the overall power consumption when using LEDs is going to be much lower than it is with HIDs.

For the most part, to know how much power an LED will use when it’s running, you simply have to look at its wattage. Keep in mind that the more LEDs you use, the more energy you’ll consume at that rate. For example, if you run a single 200w LED, you’ll be using 200w of power. If you’re running a 200w and a 300w LED, you’ll be consuming 500w of power.

Of course, you’ll also want to calculate any other accessories you need with your LED. This can be anything from timers to extra fans just in case your LED gives off more heat than you’d like. Thankfully, if you do need to cool LEDs, chances are you’ll be using a low-powered fan like a 6in Desk and Clip Fan that only uses 15w of power when running. 

4. How high do I hang an LED grow light over my plants?

In general, you’ll need to hang LED grow lights around 18 to 30in above your plants. The height of the light will vary throughout the life of your grow, though, with lights hung higher during the vegging stage and lower when it’s time to flower.

Usually during the vegging stage you’ll want around 24 to 28in of room between your light and your plants. During the flowering stage, you’ll want to lower your lights to around 18 to 20in above plants to give them more intense coverage. 

The strength of a light plays a major role in its effectiveness on your plants, too. Stronger, more intense lights will need to be hung higher in order to avoid bleaching, whereas weaker lights may need to hang closer to ensure they’re giving your plants the strength they need to grow. 

Last, make sure to keep an eye on the footprint of your light as you adjust its height. Lowering your lights will create a smaller but more intense footprint, whereas raising it will widen and soften the footprint. What you’re looking for is the sweet spot where your plants get the PPFD they need in the footprint a light provides.

5. What sort of plants can I grow with LED lights?

Truthfully, you can grow any plants with LEDs. From veggies to flowers, food to medicine, LEDs can grow what you need just as well as — if not better than — HID grow lights.

Now, we know there are issues with excess heat, but sometimes heat isn't such a bad thing. In fact, many of HID growers use heat to their advantage, especially in cold months when winter can drastically drop grow room temperatures when lights are off. This is a huge factor behind growers who are anti-LED: They don’t generate the heat energy plants need to thrive in those circumstances.

In a sense, they’re correct, because all plants need some amount of heat to survive. However, LEDs do generate some heat, so if your plants are dependent on high temperatures that LEDs may not be able to reach on their own, lower the speed of your fans so they’re not blowing so hard.

You’ll still be able to achieve the air exchange your grow room needs, but at a slower rate. If things start to get too warm, simply adjust to keep temperatures and humidity levels in check. The heat energy combined with the light intensity will create a light intense enough to have any HID purest considering switching to LEDs.