If you are considering starting an indoor garden, you’ll have to provide a significant amount of light for your plant.
LED grow lights are the newest lighting technology that is more efficient, more flexible, last longer, and generally more useful than other grow lights. LEDs are extremely efficient and, while they cost more upfront, they are cost-effective over time. LED grow lights are the best option for new growers especially, but they are quickly becoming the most popular grow light for professionals as well.
We tend to recommend LEDs over other types of lights, especially for new growers, because they are so effective and their capacity for growing is far beyond other types of lights like High-Intensity Discharge systems.
In this article, we will describe what an LED grow light is, why an LED grow light is the best choice for a grower, the different styles of LED grow lights, matching your light with your tent, how to set up your grow light, and the main considerations when buying a grow light, which includes:
- Wattage
- Coverage Area
- Light Spectrum
- Light Intensity
- Warranty
- Price
Let’s jump into it!
What Is a Grow Light?
What Makes an LED Grow Light Different from Other Grow Lights?
A grow light is a type of light that emits energy as both heat and visible light that is optimized for plant growth, which plants use for photosynthesis. We use grow lights by hanging them above the canopy of our plant so that it simulates sunlight “pouring” down onto the leaves, stems, and flowers.
A good grow light will imitate the most useful parts of sunlight. This means light on the spectrum from Ultraviolet to far-red and infrared. We measure light wavelength in nanometers (nm), and these colors range in wavelength from about 350nm to 850nm.
There are multiple kinds of grow lights on the market: High-Intensity Discharge (HID) including Metal Halide (MH), Ceramic Metal Halide (CMH), and High-Pressure Sodium (HPS); T5 Fluorescent; and Light Emitting Diodes (LEDs).
LEDs differ from other kinds of grow lights in their technology. LEDs do not rely on external ballasts, bulbs, fixtures, or even reflectors. They do not put out as much heat as HID bulbs, yet they still produce as much if not more light than HID systems. They do not require much extra equipment, they are easier to maintain, and they last much longer without dimming over time. Let’s take a look at the differences between LED and HPS, the most popular HID bulb.
How Does an LED Grow Light Work?
An LED grow light works by passing an electrical current through a semiconductor diode. These semiconductors are made of a crystalline lattice (usually of a combination of chemicals like silicone) that hold electrons. When the electrical charge changes, these electrons are forced out of the lattice and into another, breaking the bonds with the lattice in the process, which releases energy in the form of heat and electricity.
This heat and electricity are then expelled through the semiconductor and out through a small colored cover that surrounds it. Usually, these colors are cool and warm white, blue, UV-A, red, and far-red, giving the entire light a purple hue in the full spectrum.
When light falls onto a leaf, the colors penetrate into the cells and stimulate photosynthesis, the complex process of combining and changing nutrients, water, carbon dioxide, and other chemicals into sugars, amino acids, and ultimately structural components.
Plants react differently to different colors of light. Red light tends to encourage elongation and flower growth. Blue light encourages thick, robust foliage. A plant will need more blue light in its initial vegetative stage of growth than it will in flowering and will need red light throughout the entire growth cycle, but blue light still helps reduce stretching and strange elongation that can affect plant health when plants are grown only under red light. LED grow lights are excellent for growing plants because they provide the full spectrum of light needed but also can be programmed to provide a specific coloration that would emphasize better growth for your plant.
Why Should You Get LED Grow Lights?
There are a number of pros and cons to LED grow lights. Let’s look through a few.
| Pros of LED grow lights | Cons of LED grow lights |
| More efficient than other comparable grow lights like HID systems. They use just half the energy required for T5 fluorescent grow lights, are better for the environment, and they are less taxing on the electricity bill. | The initial cost of LEDs is higher than other systems. This cost might scare some first-time growers. |
| They have a higher light intensity than T5 and HID systems. You will not need to move your lights around as much as you might with HID systems, either and they can be used for the entire grow cycle. | A full-spectrum LED light is technically not the full spectrum that is produced by the sun, but you wouldn’t want that as there is a lot of dangerous radiation. |
| They produce less heat than HID systems. LEDs operate 80% cooler than HID bulbs. This is important because excessive heat leads to higher ambient temperatures, higher electricity bills, a higher potential to burn your plants, and more difficulty controlling humidity. Additionally, a cooler lamp can be placed closer to the canopy for better, faster growth. | Adjusting the spectrum usually requires specialized equipment like a digital controller. |
| They have a longer lifespan than other bulbs, usually around 50,000 use hours. That is a total of 2,080 days of constant use! Compared to HID and T5 systems, LEDs never dim over time and don’t need to be thrown out, meaning you’re not adding harmful chemicals to the environment and not having to find specialized recycling centers. | Because LEDs are very efficient, they may not produce enough heat for warm-climate plants in cold climates, especially if you’re growing plants in a garage in winter. You’ll need to add a space heater or move your grow space to a warmer part of the house. |
| LED grow lights do not require extra equipment like reflectors, ballasts, or dedicated ventilation systems. Of course, you should always have a ventilation system but you do not need one to cool the light. | There is a lack of standardization in LED technology on the market so quality between brands can vary greatly and it can be difficult to know whether a brand is an expert at producing lighting. This means you’ll need to do a fair amount of research and rely on customer reviews. |
| Spectrums can be adjusted or “tuned” to fit the stage of growth that your plant is in. This tuning is a powerful tool for growers because it helps focus energy use toward the most useful coloration for your plant. |
What to Consider When Buying an LED Grow Light
So what should you look for when purchasing a grow light? In this section, we will discuss the various factors that lead to finding a good grow light. Some of the language in this section may be technical, so we will link to definitions for your convenience! Let’s take a look at the various factors you should consider when purchasing your next LED grow light.
Wattage
Wattage determines the potential energy available to plants. The “wattage” listed on the sales page of an LED light (or other types of grow light) refers to the watts that are drawn from your home outlet, but in reality that is not the amount that is emitted and arrives at the surface. Instead, look for a conversion rate, rated in micromoles per Joule (µmol/J). A good amount conversion rate is around 2.5µmol/J.
Now, something important to remember when we are talking about light is that light is subject to the laws of physics and all the strange, quirky reality that comes with it like the fact that light is both a wave and a particle simultaneously! Light arrives as a “photon,” which is essentially the carrier of the electromagnetic force, and is the quantum form of all electromagnetic radiation, whether that be from the Sun or your grow light.
When light is delivered (falls or pours) to a surface, it arrives as a photon or a packet of electromagnetic radiation, and we can measure this arrival to help us see how effective our grow lights are at covering a surface!
We measure the number of photons that arrive in a given area through a term called the Photosynthetic Photon Flux Density (PPFD for short), which is then mapped onto what we call a Photosynthetic Active Radiation (PAR) map. Big terms, but both of these are quite important for growers! Let’s take a look at why that is.
Coverage Area
PPFD measures the number of photons that arrive in an area over a given amount of time. PPFD is measured in micromoles per square meter per second (µmol/m2/S). Usually, the higher the number the better.
A PAR map shows a comparison of PPFD spread across an area. One of these maps should be included with every grow light and they will look like the one below.
This PAR map is from the VIVOSUN VS4000. It says that the VS4000 was hung 12 inches above the floor and covered a 5×5-foot space. In the center of this map, we can see the PPFD is very high, while near the edges the PPFD is much lower, which is to be expected as the light coverage is weaker. An analogous example would be shining a flashlight in the dark and noticing that the light looks weaker around the edges of the coverage.
But how many lights can fit under each wattage of light? It’s not so much about the number of plants but rather about the size of the space, let’s take a look!
Light Intensity
Since the height of the LED grow light determines the intensity of the light, you might be wondering how high you should hang your light. It’s a great question because it depends on the kind of light and the stage of growth your plant is in. Ideally, we want intense coverage over a large area, but this is only possible with very high-end equipment, so we need to find a balance between the two and a couple factors play into this: heat produced by the light, brightness, and stage of plant growth. We have a handy chart for your reference that corresponds with LED wattage and light height.
| Light | Nearest distance (inches) | Furthest distance (inches) | Seedling height (inches) | Vegetative height (inches) | Flowering height (inches) |
| 100W LED | 12 | 24 | 16-24 | 10-16 | 12-16 |
| 200W LED | 12 | 36 | 24-36 | 16-24 | 12-16 |
| 300W LED | 12 | 36 | 24-36 | 16-24 | 12-16 |
| 400W LED | 12 | 36 | 24-36 | 16-24 | 12-16 |
| 1200W LED | 18 | 46 | 32-46 | 24-36 | 18-28 |
Light Spectrum
The light spectrum is a crucial factor for growing light. In the most general sense, there are three categories of LED grow light spectrums available: targeted (meaning blue light or red light focused) and broad (meaning white light focused). These days the majority of LED systems are full spectrum. This is because the full spectrum contains enough variation in light that allows it to cover the entire grow cycle of a plant and spectrums can be adjusted to match the current stage of growth. These tunable LEDs usually have a switch that says “Bloom/Veg” which allows you to emphasize coloration. Newer models can be programmed using controllers that can control schedules, light intensity, and spectral range.
Plants mainly utilize light that is within the visible spectrum or just outside of it. Therefore, grow lights aim to produce the exact coloration that plants desire – this allows for the most efficient use of electricity while having the best results.
We measure color wavelength in two ways: nanometers (nm) and Kelvin (K). Nanometers refer to the actual wavelength of the light, measured from peak to trough, while Kelvin refers to the “temperature” of the light.
Plants go through four main stages of growth: germination, when the seed sprouts its taproot and first shoot; seedling, before the seed grows its first set of true leaves; vegetative growth, when the plant has its first set of true leaves until it matures to be ready to flower and reproduce; and flowering, when the plant produces flowers for reproduction and is mature enough to spread its fertilized seeds.
Through each stage of growth, a plant will utilize a specific coloration to produce the amino acids that it requires to build the structures of that stage. The germination stage does not require specific light so we will omit it here. Let’s look at the details.
| Stage of Growth | Color Preference (higher -> lower) | How the light is utilized (sources: 1, 2) |
| Seedling | Blue, blue-green | Blue: The opening and closing of stomata; helps develop thicker, robust foliage; stimulates amino acid production for structural compounds (1) |
| Vegetative | Blue-green, red, ultraviolet | Blue: The opening and closing of stomata; helps develop thicker, robust foliage; stimulates amino acid production for structural compounds (1); Red: promoting elongation and growth, mediating flowering (2) |
| Flowering | Red, blue-green, infrared, ultraviolet | Red: promoting elongation and growth, mediating flowering (2)
Blue: The opening and closing of stomata; helps develop thicker, robust foliage; reduces stretching (1) |
Warranty
Most grow light manufacturers offer warranties on their products, which is a good thing. LED grow lights can last a very long time and you should be able to plan for that to be the case – if a grow light fails it can be devastating to your plants and it should be the responsibility of the company to take care of your lights when there is a defect. Since grow lights last around 50,000 hours, the company should cover the entire period for defects or component issues. VIVOSUN offers warranties on LED grow light systems that range anywhere between 3 to 5 years, so you know you’ll be covered.
Price
Price is the most crucial component in decision-making for a new hobby. LEDs tend to be a little more expensive than HID or T5 systems but the cost saved in electricity over time is worth the initial startup. Let’s take a look at the price range for various types of LEDs – the price is a range because the larger the grow light, the more expensive it will be.
| Light type | General price range (dollars) |
| LED board | $70 – $500 |
| LED bars | $150 – $500 |
| Traditional LED panels | $100 – $400 |
Styles of LED Grow Lights
There are three styles of LED grow lights on the market today. These differences end up affecting cost, form, light distribution, and application. Let’s look at our different options!
Traditional Panels
The VIVOSUN 1200W COB LED Grow Light
These traditional LED grow light panels range in wattage from 100W to 1200W and have a varied grid pattern of diodes. They are compact, easy to use, usually have a “Veg/Bloom” switch, and can be connected to other panels to be controlled simultaneously. These are usually a mixture of a “chip on board (COB)” LED and a “quantum” board. These are the first popular iteration of LED grow lights on the market but have lost in popularity to the quantum board style LED.
Quantum Boards
LED quantum boards are a low-wattage, high-efficiency version of traditional panels. They’re more efficient, they are usually lighter, they radiate heat better, and they usually have a dimmer built into the integrated driver. They produce excellent yields without using too much power from your wall outlet.
LED Bars
The VIVOSUN VSF4300 Foldable LED Grow Light
LED bars are a high-efficiency style of LED lighting with an external ballast/driver that extends the lifespan of the fixture. They weigh a bit more than other models but they are extremely efficacious and provide excellent coverage, usually in a rectangular form. Some models (like the image above) are able to fold in half so that growers can use even less wattage and easier to store. These are mostly utilized by professionals with very large grow operations.
How to Set Up an LED Grow Light
Hanging a grow light is easy and most grow lights come with the equipment to set everything up. Be aware that HID and T5 bulbs are just that, light bulbs, so you’ll need to get a ballast and a reflector before you are able to use your light. With LEDs, you can simply hang them and then plug them in.
Regardless, the process of setting up your lights is simple – VIVOSUN includes rope rachet hangers with every light so set up is simple.
Step 1: Gather your supplies.
Step 2: Hook the metal hangers (if included) to your light. Next, connect the carabiners on the rope rachet hangers to the hoops on the metal hangers.
Step 3: Hang the long end of the rope hanger on the cross bars, loop it over the bars, and connect it to the rope.
Step 4: Pull the free end of the rope that runs through the rachets to raise the light to the position that you need for your plants.
We hope this long article helped prime you for your purchase. We strongly recommend investing in LED lighting in your grow space because LEDs are more efficient, will help you save money over time, are excellent at producing great yields, are compact, don’t produce a lot of light, and last a lot longer than other systems.
Grow Light Lumens Chart
| Stages | Description |
| Seedling Stage |
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| Vegetative Stage |
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| Flowering Stage |
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More Information about Light Distance and Light Intensity:
How Far Away Should My Grow Lights Be?
How Far should Seedlings be from Grow Light ?
What’s the Best Grow Light? Unveiling the AeroLight Revolution by VIVOSUN
What You Need to Know About Grow Lights?
How Many Grow Lights Do You Need?
As always if you have any questions you can message our Instagram or Facebook and we’ll be glad to help you out! We’re happy you’re on this journey and we want to help in any way we can.
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