The Ultimate Guide To LED Grow Lights
By Chloe
Hello and welcome to your guide to understanding LED grow lights. Glad to have you along today and I hope you learn everything you want to on our tour. I also hope to get a laugh or two out of you along the way.
I guess I should introduce myself. I’m Nate, plant enthusiast and proud owner of LEDGrowLightsReview.org. Chloe (who runs this site) was gracious enough to let me share some of my expertise here on her site. By the end of this guide I hope you can understand why more and more indoor plant growers are starting to make the switch from high-intensity discharge (HID) lights to light-emitting diode (LED) grow lights.
Let’s take a look at what’s on the agenda today.
Table of Contents
- How LED Grow Lights Work as a Substitute for the Sun
- Six Criteria for a Good LED Growing Light
- Heated Debate: LED vs HID
LED Grow Lights Work as a Substitute for the Sun
Plants really don’t need much to grow; they simply need carbon dioxide, water, and light. One interesting fact is that plants don’t actually need dirt or soil to grow. There is a whole field of growing called hydroponics that is based around the idea of growing plants without soil.
Anyways, in a semi-miraculous process called photosynthesis plants take water and carbon dioxide and turn them into food (sugars). This food helps the plant grow strong and tall; unfortunately it helps us grow in a different direction (the whole process is summarized in the graphic below).
Lighting
In today’s guide, we aren’t really going to worry as much about carbon dioxide and water. We’re going to be talking about lighting. As mentioned above plants absorb light and they use the energy from the light to turn water and carbon dioxide into sugar (food).
For the most part people use the sun to grow any plants they might have. Unfortunately, the sun isn’t always available. In some parts of the world (depending on the time of year) the sun is only available for a few hours each day. In addition, some people like growing plants indoors where the sun’s rays don’t penetrate. Not having sunlight makes it difficult to grow. Fortunately, scientists have developed growing lights that plants can use for photosynthesis without ever needing a single ray from the sun.
Quick History of Growing Lights
Not too long ago growing experts found that metallic-halide lights and high-pressure sodium lights worked extremely well for growing plants. These lights are collectively called high-intensity discharge lights. Even more recently, NASA scientists discovered that LED lights could be used to grow plants. LED grow lights are quickly gaining popularity because they are much more energy efficient than HID lights.
What do LED Grow Lights Look Like?
Above is the picture of one of the more popular LED growing lights out there. Each grow light is made up of tens or hundreds of individual LED bulbs (depending on the size of the grow light). For example, a 90 watt grow light might be made up of 90 different one watt bulbs. Below is a picture from Encyclopedia Britannica of what these individual LEDs look like.
We won’t go into all the details here about the science behind how these lights work (frankly, it gets pretty complex and would probably bore you to tears). This picture is worth taking a look at though so you can see what these individual LED “bulbs” look like.
Six Criteria for Purchasing a Quality LED Grow Light
Not all LED grow lights are built equally. There are six characteristics that I recommend you look at before purchasing one of these grow lights.
1. Warranty – Most of the quality LED lights come with at least a one year warranty. Some of the most expensive lights come with a five year warranty. Look for a light that at least has a one year warranty (if at all possible find one with a three year warranty).
2. Trial Period – Since this is a semi-new technology there are a few people out there trying to take advantage of first-time buyers. Make sure you buy a light that has at least a thirty day trial period. This way, if you notice that the light is having no effect on your plant, you can send it back.
3. Actual Watts Drawn – The nature of light emitting diodes is such that a 1 watt diode doesn’t actually draw 1 watt. There is some complex science behind it, but the truth of the matter is that a 1 watt diode might only draw .7 watts. What this means is that a company will list their light at 100 watts when it really only draws 70 watts. The actual watts drawn are what you want to pay attention to. Most companies will list this if you look at the fine print; however, there might be some cases when you need to ask. Don’t be fooled into purchasing a 500 watt light that actually only draws 40 watts.
4. Heat Sink – When someone complains to me that their LED grow light didn’t last very long, the first thing I want to see on the light is the heat sink. Overheating of the LED chips will often cause them to break. This means that a good heat sink needs to be put in place. First of all make sure that the light you are thinking about purchasing has a heat sink. Second make sure that the heat sink is made of copper or aluminum. Third, make sure the heat sink has quite a few fins on it. Heat sinks are confusing so I’ve included an illustration of one below.
As you can see in the picture above, the heat sink absorbs the heat from the LED chip. If the heat sink weren’t in place, then the light wouldn’t last very long. Note that there is usually a fan built within the light that blows air at the heat sink. The fins are important because they catch the wind from the fan and dissipate the heat quickly.
5. Spectral Wave Length – Spectral wave length is a big deal with LED lights. Remember from your high-school science classes that wave-lengths are classified by color. Red wave lengths are long and blue wave lengths are short.
One of the most exciting features about LED grow lights is that scientists can control the exact spectrum or colors of light emitted from them (the sun and HID lights emit all of the colors, humans can’t control them). This is a big deal because scientists have found that plants don’t use all the different colors of light when they are growing. This is readily apparent in the fact that plants are green (they are reflecting green light).
So why is spectral wave length a big deal when purchasing an LED grow light? Well, growing experts have found that red light induces flowering on a plant and blue light induces vegetation or growth. If you want one of these lights to help your plants flower, then make sure you buy one that emits light in the red wave-length spectrum. If you want a light that will help during the early stages of plant development (germination and vegetation) then make sure you get a light with a lot of the blue wave-length in it. If you want a light that will do it all, make sure you find one that has both red and blue light. This information should be readily available from any company you purchase these lights from.
6 – Beam Angle -The last important thing you’ll want to look at when buying one of these lights is the beam angle. There are three standard beam angles out there: 60 degree, 90 degree, and 120 degree angles. The 60 degree angle is much better when you are dealing with a taller plant. The light beam is more focused and intense meaning that it can get down to the lower levels of your plant. The 120 degree angle is better for covering a wider area. For instance you may want a light with a 120 degree light when you have several short plants that you want to grow under one light.
LED VS HID: The Great Debate
Many people want to know whether they should buy an LED grow light or an HID grow light. Well, I can’t answer that for you but I can give you some of the pros and cons of each light.
LED Advantages
- Efficiency – LED lights are much more efficient than HIDs. In other words they use a lot less energy.
- Heating – LEDs don’t put out near as much heat as HIDs. This means that you don’t have to spend as much money on cooling.
- Lifetime – Most LED grow lights last around 50,000 hours. HIDs last around 10,000 hours.
HID Advantages
- HIDs cost less initially. LED grow lights are expensive up front. It’s worth noting that many people think that LED lights save money in the long run due to electricity and heating savings.
- HIDs have a proven track record. They’ve been around a lot longer and more people know how to use them.
Conclusion
Well that wraps up our tour of LED grow lights. I hope you’ve learned more about these lights and why so many people are starting to use them. A special thanks to Chloe for letting me get the word out on her site. If you have time, stop on by my site to read my LED grow light reviews.
Tagged with: led grow light • led grow light reviews • LED Grow Lights