Grow-Lights-FAre you ready to choose an LED grow light now

9 Things You Need to Know When Purchasing LED Grow Lights



LED growth lights bring significant benefits, but choosing the right product often proves to be very challenging. The various models that appear on the market, the manufacturer’s confusing statements and misleading product descriptions are some of the main reasons behind it.

Starting with the wrong lights can have a negative impact on your growing efforts, so an informed purchase is a must. There are many factors and attributes to consider, but you should also understand your growth goals, location, and other details involved.

Here are some of the most important things I learned from LED growth lights. If you are new to LEDs, I hope this will speed up your learning curve. If you are an expert, please share a comment that can help.

  1. Spectral Output and Wavelengths
  2. What is Lumen?
  3. What is PAR?
  4. Plant Growing Space
  5. Heat Generated By Grow Lights
  6. CFL, HID or LED?
  7. What is Your Budget?
  8. Brand Reputation


#1 Spectral Output and Wavelengths

When discussing light, spectrum simply refers to a range of wavelengths of visible light in the entire electromagnetic spectrum. Aside from visible light, the electromagnetic spectrum includes energy (radiation) from radio & microwaves, infrared, ultraviolet, x-rays, and gamma rays.

Thankfully the spectrum we’re referring to is the light spectrum, which- in the grand scheme of things- is relatively small. Even better, when it comes to growing plants there are really only four wavelengths of light we consider: blue (cool, 400-520nm), green (neutral, 500-600nm), red (warm, 630-660nm), and beyond red (hot, 720-740nm).

These wavelengths are vital when it comes to growing plants because they will allow a plant to process light and sugars properly, as well as encourage your plants to grow and protect itself in various ways.

Violet and Blue Wavelengths

Ah, the cool wavelengths of light. These include UV (200-380nm), Violet (380-445nm), and Blue (450-495nm). These wavelengths are responsible for developing the structure and health of the plant, so it’s important that you try to expose your plant to as many of these wavelengths as possible during its life- in moderation, of course.

Studies show that violet wavelengths are responsible for strengthening plant cells against sun/light damage. Along with antioxidant enhancement, this wavelength helps the plant’s attractive features like the color and scent.

It should be noted that violet is its own wavelength, and should not be confused with the purple/violet you get when you mix blue and red wavelengths.

Blue wavelengths are vital in the development and processing of chlorophylls and carotenoids. As you probably already know, chlorophyll’s play an important role in turning light and nutrients into chemical energy for your plant to grow. Carotenoid’s help capture light and get rid of some of the excess energy from that light. In this wavelength, all of this development is heightened, which is why you use so much expansive growth with this wavelength.

Red and Far Red Wavelengths

The red wavelengths of light are considered the warm wavelengths along the light spectrum. This includes the red (630-660nm) wavelength and far-red (720-740, IR) wavelength. Cool wavelengths and warm wavelengths contribute chlorophyll processing, but warm wavelengths aren’t as intense as cooler ones.

That’s why you don’t see so much explosive growth with flowering lights. What you do see, though, is gradual growth that will contribute to the strengthening of stems, the growth of leaves, and eventually vegetation and fruit.

The red wavelength is most abundant during the summer and autumn parts of the year, which is usually why you use it during the flowering stage of growth: that’s what they’ll flower with naturally.

When these wavelengths stimulate your plant more intensely and for longer periods of time than in vegging, it will trigger your plant to activate cells to specifically start producing flowers. Because your plants need more strength at this time of year to grow its harvest, this wavelength is also responsible for helping strengthen stems to hold the fruit it’ll produce.

In order to grow most efficiently, many plants need light in the red and blue spectrum, but also infrared and ultraviolet, depending on the stage. A powerful full spectrum LED grow light enables you to cater to the plant’s specific needs by providing the proper photosynthetically active radiation values.


#2 What is Lumen?

From a purely scientific point of view, lumens is the amount of light emitted by a given source per second. Sounds easy?

If you’ve been sitting in a room with a dim light bulb, you’ll probably get drowsy after a while, because the light bulb is not enough to make your body think it’s still white Go to sleep.

On the other hand, a bright light bulb would make you more attentive and focused on the task at hand. Their plants are similar, but there can be more. Without enough light, they just do not work and their lamps are lumens.

What is the difference between lumens and watts?

If so, what is it? Well, what is it about?

Watt is a measure of energy consumption and almost independent of light. It turns out that LED lamps consume much less than conventional incandescent lamps, which means that the light consumed between 6 W and 10 W can actually produce the same amount of light as a 50 W halogen or fluorescent lamp. This is because it produces the same amount of lumens at lower energy levels. Lumen the light you use.

How many lumens do you really need?

How many lumens do you really need? There are many different factors. You need to see how big your space is, what kind of plant you are planting and what kind of yield you are looking for.

There may not be an ideal number, but in general, your plants should thrive well if you can produce 300 to 800 lumens per square foot.


#3 What is PAR?

what is par

Basically, PAR is the amount of light that is actually available during photosynthesis. There may be more light coming from a particular source, but your plants are not making the most of them – some of which have no real impact on the photosynthesis process. It is best to use an example to explain this.

For the human eye, a bright white or yellow light bulb seems to illuminate the room most effectively, while blue or red light looks very dark in our eyes.

So for us, we prefer brighter The light bulb illuminates the room. But plants prefer blue light and red light.

Traditional bulbs can have high lumens, but they are not necessarily very high at the PAR level. When exposed to blue and red light, the plants undergo optimal growth, and this type of light, while still visible to the human eye, is better measured in terms of PAR than with lumens. As part of the visible chromatogram, blue and red light were found between 400 nm and 700 nm, and when approaching 700 nm, PAR exposure increased.

When a plant grows from a seed to a mature plant, it needs to go from the blue to the red end of the spectrum, and you can measure its amount of light in nanometers by using a special instrument – the closer the light is to 700 nm, the higher the PAR reading. As long as your plants remain at the appropriate level between the 400nm and 700nm ranges at each stage of the plant’s growth cycle, you will end up with healthy and productive plants.


#4 Plant Growing Space


Space availability is a vital factor when purchasing lighting as it determines the amount and size of lamps you need.

The first thing you need to do is measure the exact size of your garden. Then you need to find out the lighting area size of the lamps you’re considering in order to determine the exact number you need.

The general guideline most growers use is that you need 32 watts of actual power per square foot if you’re growing high-light plants like tomatoes. Low-light plants like lettuce need somewhere between 11 and 18 watts per square foot.


#5 Heat Generated By Grow Lights


Heat From Fluorescent Grow Lights:

  • CFL, T5, and T8 will typically have modest power draws and efficiency. Will generate more heat than an LED but less than HID lights.
  • Heat From HID (High-Pressure Sodium / Metal Halide): Will generate significant heat, may need to use with fans or other tools for ventilation. To get the powerful benefits of HID lights while reducing the heat creation, ceramic metal halide (CMH) grow lights offer less heat output but are more expensive than HPS or MH.
  • Heat From LEDs (Light Emitting Diodes): Minimal heat, high efficiency. Heat output decreases typically as price & quality increases.

Why is less heat good for a grow light?

There are at least 2 major reasons:

  1. Excess heat can burn plants and otherwise reduce yield.
  2. Excess heat means less visible light output which your plants can use for every $ spent.

Now, how do different grow light heat outputs compare?


#6 CFL, HID or LED?


  1. CFL (fluorescent light)
  2. HID (high intensity discharge)
  3. LED (Light Emitting Diode)


The CFL is best suited for small-scale growth by non-professionals and is usually not measured in terms of cost or prior.


  • Cheap
  • Suitable for small growth
  • Available in many stores
  • Suitable for any standard luminaire
  • Available in a variety of color temperatures


  • Low light output compared to other types of bulbs
  • Need to be close to plants
  • Need to use a few
  • Not suitable for greater growth efficiency
  • Not suitable for intermediate/experienced growers


For most commercial applications, HID is still the best size, although with the rapid development of LED growth lamp technology, LEDs have fewer advantages in scale.


  • Lower cost than other high quality lamps
  • Produced good results
  • Easy to set up and operate


  • Produces a lot of heat, requires ventilation and exhaust
  • Limited life
  • Do not insert a normal socket
  • Need special hood and ballast
  • Can increase the electricity bill


LED is the most developed growth light technology in the past decade. It offers many scalability advantages that neither CFL nor HID can provide.


  • The most energy-saving growth lamp
  • Almost no heat
  • Plug in a standard socket
  • Long life


  • High initial cost

If you are interested in scalability and are willing to invest in the long-term growth of your growth lamp system, then the upper LED will once again be the best way.


#7 What is Your Budget?

Comparison led clf hid

One of the most important metrics to consider when buying your first grow light is the price of the grow light.

The good news for grow lights is this: there are a lot of options at all price points.

$: CFL bulbs: can be found on Amazon for less than 10 USD

$$: T5, T8, T12 fluorescent: good value for less than 100 USD. A 4 tube T5 grow light system can generate multiple hundreds of dollars worth of produce in a year (1-2 year pay back period with all other costs factored in besides lighting).

$$$: LED and High Pressure Sodium (small sizes): most LED solutions will be on the pricier side relative to fluorescent, if you are going to spend on LED’s, your best option is to invest in a light from a well established LED vendor (full explanation in the next section “Vendor Quality”)


#8 Safety Risk


Not all growth lights have the same safety risk.

The two key areas through the growth of optical security assessment are:

  1. How fragile light is
  2.  Materials in which light itself exists.

In both categories, LEDs have significant advantages.

  1.  For home growing projects where pets or children may disrupt lighting, LEDs are less likely to rupture when knocked or pushed due to the small size of the diodes and the way they are placed in the fixture. Other lighting systems, such as fluorescent tubes and HPS lighting, can be very fragile and can break or even explode if struck with enough force.
  2.  The following are factors you should consider when making indoor lighting lights:
  •  Fire – A common misconception is that the fire that starts the growth lamp is only caused by heat. Many fires caused by growing lights are electrical fires caused by incorrectly designed incorrect power supplies for growing lamps
  • Mold – When the lamp is cycled, the moisture content in the growth space changes. This changing moisture (lighting = low moisture, light extinguishing = moisture condensation) increases the risk of mold or mold, which can be harmful to humans.
  • Mercury – Many types of growth lamps, in addition to LEDs, have a large amount of mercury. The main problem is that if these lights break, they can pose a health risk – anyone in the growth room may inhale mercury, which can cause damage.

In many of these areas, LEDs offer the best security, albeit at the highest price.


#9 Brand Reputation

There are many different brands on the market, each offering a slightly different product. This makes the selection more difficult considering that not all options have the same quality.

For growing lights, ratings and reviews on sites like Amazon, Alibaba, or even niche sites for grow lights may not guarantee you are receiving the product quality you paid for.

If you want to know the different lighting options that are almost equal in price and appearance, then look at the brand to provide an answer. As in other fields, companies with a good reputation, long history and extensive research and development are more likely to have good products. If you are planning to make a purchase on Amazon, the following brands are worthy of reference:

  • Apollo Horticulture
  •  PlatinumLED Grow Lights
  •  Hydrofarm
  •  Roleadro
  •  Galaxyhydro
  •  KingLED
  •  JCBritw
  •  Dimgogo



Plant Grow lights are revolutionizing the way we grow plants, enabling both professionals and enthusiasts to achieve optimal environment efficiency with minimal effort. The advantages are numerous, with just a few of the main ones mentioned below:

  1. Spectral Output and Wavelengths
  2. What is Lumen?
  3. What is PAR?
  4. Plant Growing Space
  5. Heat Generated By Grow Lights
  6. CFL, HID or LED?
  7. What is Your Budget?
  8. Brand Reputation

Are you ready to choose an LED grow light now?




  2. Does Your Grow Light Have What Your Need For Your Next Harvest? by Devin Martinez
  3. 11 Core Guidelines To Know Before Buying Grow Lights
  4. Working in Wavelengths
  5. Wikipedia-Lighting units
  6. Sylvania Gro Lux Wide Spectrum
  7. CFL &  LED Bulb Comparison / Advantages / Safety Hazards


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