The 10 Best LED Grow Lights
This wiki has been updated 35 times since it was first published in September of 2015. While indoor grow rooms have traditionally been illuminated by metal halide and high pressure sodium fixtures, supplemented by the odd compact fluorescent to help with seedlings and clones, advances in technology over recent years have made LED grow lights a viable alternative. Our selections for this category include picks suitable for casual hobbyists as well as dedicated professionals. When users buy our independently chosen editorial picks, we may earn commissions to help fund the Wiki.
August 03, 2020:
During this round of updates, while most of our previous selections proved to still be worthy picks, we did end up replacing the Viparspectra V1200 with the Viparspectra 2020 Pro Series, which, among other improvements, includes a new solid-state cooling system that relies on a large aluminum heat sink in lieu of its four, former cooling fans, which tend to be noisy and are prone to eventual breakdown.
We also added the Spider Farmer SF-2000 — which caught our eye with its Samsung and Mean Well components, as well as the the Ezorkas Tri Head and Barrina V-Shape — two relatively low-powered models that we thought were worth including for the portion of our audience that isn’t interested in launching a commercial cannabis operation, but rather is just looking for a bit of extra light to help speed things up with their indoor herb garden or countertop microgreens.
This can be an extremely confusing category to shop in, especially for users who don’t have any sort of background in electrical fundamentals or indoor gardening. With prices varying so drastically and every company trying to impress you with a different set of numbers, it can be difficult to suss out the good and the bad. With that in mind, here’s some basic terminology to arm yourself with while you shop:
Wattage: Let’s start here. For old-school growers who are used to comparing nominal 400-, 600- and 1,000-watt fixtures, this is going to be a bit of an adjustment, but my advice here is to do your best to forget about wattage. The way some companies advertise their gear – calling a light with 400, five-watt LEDs a 2,000-watt fixture, without taking efficiency into account – can be extremely misleading, and enough to give the uninitiated a headache. As far as wattage goes, for all practical purposes you should only be worried about your input wattage, as it speaks directly to how much this fixture is going to cost you in electricity.
Photosynthetically Active Radiation (PAR): This is the name given to the range of light that plants use for photosynthesis. Just as there are shades of ultraviolet and infrared that are invisible to the human eye, plants can only see light that lands on certain parts of the spectrum, specifically, between 400 and 700 nanometers. Put simply, PAR is the part of the light spectrum that matters to plants.
Photosynthetic Photon Flux (PPF): This is the metric used to measure a given light’s PAR output at the fixture, measured in micromoles per second. Note that this doesn’t describe how much light is getting to your plants, but rather simply how much is being released from the fixture at the point of origin.
Photosynthetic Photon Flux Density (PPFD): Quite possibly, this might be the most important metric to consider when shopping for your new lights. PPFD is a spot measurement that calculates micromoles per second, per square meter. Essentially, this measures how many viable photons are going to reach your plants when they're positioned a certain distance below, and a particular distance from, your lights.
Savvy marketers provide their audience with detailed diagrams, sometimes referred to as PPFD maps, that clearly detail their light’s intensity. These diagrams can be helpful, especially for growers looking to equip large areas and trying to calculate proper spacing, but the notoriously skeptical consumer in me can’t help but wonder about their accuracy. Master growers have been known to keep a light meter on hand, so they can confidently fine tune the spacing in their gardens, to maximize yield.
April 23, 2019:
While the G8LED model that topped our last selection maintained its number one ranking, our previous second best has been unseated by the likes of the Viparspectra V1200. That's more to do with the incredible heat handling capabilities of the V1200 than it is to do with anything necessarily deficient in the California Light Works model now living at number three. A few items left our list entirely, as well, including a less advanced model of the Roleadro Galaxy Series and an older Miaxisun, both of which have been replaced by models far more flexible from the same brands.
We wanted to make sure to keep the rather simple Aspect model around, as well. It's not going to be anybody's go-to for industrial applications, but it's more than sufficient to please a plant or two that's struggling through a grey winter or having to move into a darker room in the house.
Light Above All Else
Without light and photosynthesis, sustaining life would be very difficult.
If indoor horticulture fascinates you, then you're going to need a good alternative to help those beautiful flowers bloom inside your home or business. While fertile soil, plant food, plenty of water, and using the best seeds are definitely important, there's an additional component that can make or break your success in the garden and that's light.
Without light, your plants don't get the all the nourishment they need. Without access to an outdoor garden or lots of land around your property to cultivate one, the next best thing would be to move that garden right into your own home with the use of indoor grow lights.
While grow lights come in several different forms, they are all artificial electric light sources with a common goal of stimulating plant photosynthesis through the emission of an electromagnetic spectrum. Photosynthesis is the process by which plants convert light energy into chemical energy, which is then used to fuel growth activities. Fortunately for us and most life on Earth, the main waste product for plants during photosynthesis happens to be oxygen. Without light and photosynthesis, sustaining life would be very difficult. Grow lights provide either a light spectrum similar to that of the sun, or a particular spectrum best suited for cultivating a unique species of plant, depending on what it is you actually want to grow.
Your main goal is to mimic outdoor conditions as closely as possible with respect to what your plants would ordinarily experience in their natural outdoor environments to propagate. That said, you need versatility in your grow lights to deliver various colors, temperatures, and spectral outputs. Common types of grow lights include incandescent lamps, fluorescent lights, high-intensity discharge lamps, and light-emitting diodes.
What gives LED grow lights an edge over some of their competition is their versatility, efficiency, longevity, and friendliness to the environment among other things. Diodes also allow for specific wavelengths of light to be produced. This means that LED grow lights can cover a broad spectrum of colors that include the red, green, and blue parts that plants use to grow and flourish.
Finally, LED grow lights are not only used for industrial and home applications on Earth, but they also play a role in farming for a possible future with respect to hydroponics and sustaining plants in outer space. Does that mean we're ready to start terraforming Mars? Probably not, but it could be a first step in the right direction.
Let There Be Light
There are several things to consider when choosing an LED grow light, such as what you plan to grow, where you plan to grow it, and how much space you have. The good news is that LED grow lights offer you the freedom to make the best decision possible, regardless of what plants you intend to cultivate.
Go with LED grow lights equipped with the ability to disperse some of that heat to ensure the longevity of the LEDs themselves.
Plants and lights are generally placed within close proximity to one another, which is ideal when working with limited space. You also want to be sure that the spectrum being represented will cover the plant surfaces and not just the surrounding areas. LED grow lights encourage plant propagation without sacrificing huge amounts of money or wasting electricity.
Many LED grow lights are designed to give you large yields per watt, while some feature built-in spectrum controls for fine-tuning the resulting light at each stage of the growing process. Adjustable spectrum controls are quite important when growing a variety of fruits or vegetables like tomatoes and cucumbers, as there isn't a universally optimal light recipe for every plant. Required light intensity and total exposure time can and will vary for different plant species, so it's important to keep these things in mind when determining your needs.
Choosing high-powered, brand-name LEDs gives you the confidence that your grow lights have been adequately tested and that they will stand up to the life expectancy needed to keep your plants alive and healthy.
With high power also comes heat. Go with LED grow lights equipped with the ability to disperse some of that heat to ensure the longevity of the LEDs themselves. Solutions for this include heat sinks and electric fans built into the LED light fixtures. While heat isn't necessarily detrimental to your plants, you don't want it to shorten the lifespan of your lights.
A Brief History Of Grow Lights
Grow lights for plants have a history of nearly 150 years, starting with Thomas Edison's invention of the incandescent filament lamp as early as 1879. Along the same parallel was open arc lighting, which made use of carbon rods as a popular form of street lighting in the late 1800s as well as for continued plant testing through the 1940s.
Enclosed and low-pressure gaseous discharge lamps were originally developed with mercury vapor in the late 1800s and were expanded around 1900 to include other elements such as sodium, neon, and argon. The use of phosphors in conjunction with the low-pressure mercury lamps further encouraged the development of fluorescent lamps during the 1930s. Compared to mercury lamps, fluorescent lamps had a broader spectrum, improved efficiency, and a longer operating life when compared to incandescent lamps.
The 1930s to 1960s saw further development of high-pressure mercury, metal halide, and sodium lamps that are still being used today to supplement naturally-lit greenhouses.
It wasn't until around 1990 that the LED grow lamp underwent its initial testing to eventually become a common means for plant propagation in today's horticulture industry.