Best LED Grow Lights
In this article we’ll discuss what LED Grow Lights are, what are the benefits, and how to choose the best LED grow lights for you.
LED Grow Light Overview
For decades, indoor growers have relied on artificial light sources such as HID, High Pressure Sodium, and Fluorescent to mimic the sun’s rays in an indoor environment. Whether used for Hydroponics Systems or Aquaponics Systems, these light sources all have varying degrees of effectiveness. Now there’s a new player in the game, LEDs (Light-emitting Diodes), and it’s a technology that’s been around for decades, mostly as instrument panel indicator lights, but only recently are LEDs being applied to higher intensity light uses such as indoor growing.
The primary benefits of LED, over the more established light sources, are significantly reduced heat and reduced power consumption. Because they produce less heat than the more commonly used HIDs, they are more energy efficient and require significantly less expense to ventilate and cool.
The Myth of the LED Watt
If you’ve been researching the best LED grow lights for more than about 30 seconds then you’ve probably noticed that most manufacturers give each of their models a Wattage rating. At first blush it may seem like the more Watts you get for the fewest dollars the better. Unfortunately, for most of the LED grow lights on the market, even several of the ones we recommend, those numbers are simply not accurate. Often times they represent the max output of the LEDs in the light, but these lights are very infrequently capable of outputting anywhere near those numbers. (example; A 3W LED is typically run at 1-2W to extend the life of the LED, however many manufacturers put 100 3W LEDs in a light and call it a 300W light). Add to that the fact that the wattage numbers are, theoretically, simply a measure of the energy going into the light, and not a measure of what is emitted by the light and you have a bit of a conundrum.
It’s important to understand a few more things. First, a light’s outputs are both heat and light when energy is the input. Light is what we want, heat is not. The more heat a light put’s out the less light it is putting out from the same amount of energy input. This is why traditional forms of lighting (Incandescent, High Pressure Sodium, etc.) get so hot and are so inefficient. LEDs save energy because they don’t get as hot. Pretty simple, right? However, some LEDs get hotter than others and some emit less useful light colors than others (more on that later). This makes it very difficult to make an apples to apples comparison between LED grow lights.
Ultimately, we will use estimated Actual Watts for our comparisons, since Claimed Watts are unreliable, and accurate output data is not available for many of the available lights.
Understanding Light Cycles
Plants have evolved to grow well under light cycles that the Earth provides them outdoors. Long bright summer days and shorter less bright Fall and Spring Days. This is why it is best to replicate these light cycles when growing indoors. The following light cycles are recommended (by growth phase)
- Seedling/Clone Phase: 16+ hours on, 8- hours off
- Vegetative Phase: 18 hours on, 6 hours off
- Flowering Phase: 12 hours on, 12 hours off
The change in light cycle will actually help trigger the plant to move on to the next growth phase, specifically from Vegetative to Flowering. It’s also important to keep in mind that some plants react poorly to interruptions in their light cycles. Turning a light on in the middle of a dark phase, perhaps to check on your crops, can be detrimental to overall yield and should be avoided.
How much light do I need?
As a general rule of thumb, you want approximately 25 actual watts per low light plant (lettuce, herbs, etc.) and about 50 actual watts per high light plant (tomatoes, cannabis, peppers, etc.). Manufacturers will often give a coverage area, which is helpful, although often overestimated, but we find it more helpful to account for the number and type of plants being grown to determine which grow light is best.
As we discussed earlier, plants require different light at different phases of their growth. Some manufacturers have built the capability to switch spectrums into their lights. Unfortunately, tests have shown that plants do not react well to an abrupt shift in spectrum and their growth can actually be hindered for a period of time while they adjust to the new spectrum.
Dimming at Dusk and Dawn
Although a nice feature in some aquarium lighting, there is no compelling evidence that dim light in the early morning and evening actually help plant growth. When it comes to plant growth, less light is less light. Most plants need a dark cycle for a period of time, usually at night, but a simple on-off cycle is sufficient. The KISS (keep it simple stupid) principle applies here.
LED Grow Light Bulbs
A note about LED Grow light bulbs: Although they may seem tempting at $20-$30, we would recommend steering clear of these bulbs. At a claimed 12-40W output, with actual Wattage draws likely in the 4-15W range, these lights are simply insufficient for all but the smallest plants with the lowest light requirements. Unless you’re looking to grow a single lettuce or herb plant, avoid these bulbs.
Finally, it’s important to point out that, like most things in life, you generally get what you pay for. There are many VERY reasonably priced LED grow lights on the market with generally happy customers in the short term. These lights are certainly a great place to start for the beginner, and one even received our Editor’s Choice award, just don’t expect that they’ll last more than a few years and you shouldn’t be disappointed.
Below you’ll find our analysis of many of the most widely available and best LED grow lights on the market today. We have compared them based on a number of factors including $ per Actual Watt, Spectrum range (LED colors), including UV or IR, warranty, returns, reviews, etc. Our ratings are designed to take all available factors into account. Immediately below you’ll find a quick reference table showing each light’s features at a glance. Scroll down below the table for a detailed look at each light.
Quick Reference Table
Thanks for reading our Best LED Grow Lights page! We hope you’ve found this information helpful. For more grow light reviews, please see our LED Grow Light Reviews, COB LED Grow Lights, Grow Lights for Weed, and Small Grow Lights articles. We also have dozens of other pages about hydroponics and aquaponics which may be of interest to you, including our DIY Aquaponics Plans, Hydroponics Grow Media, Hydroponics System, AeroGarden Reviews, and Marijuana Grow Supplies articles. Best of luck with your grow!