Full spectrum LED grow lights are must-haves for indoor gardeners, but choosing between them can be difficult. We all know that plants need light to survive. This is especially relevant to high light plants such as succulents and cacti. Additionally, plants naturally growing in temperate sub-tropical climates need it as well. Many popular houseplants are tropical species that naturally grow in bright, warm habitats. These typically receive at least 6–8 hours of sunlight per day.
In contrast, plant families such as the Alocasias, Monsteras and Philodendrons thrive in low light levels. This makes them perfectly happy in shady spots indoors. Most plant families, however, are happier long term in a lighter and brighter situation.
Unnaturally low light levels can cause your plants to become stressed. Their form will become abnormally stretched in their search for light, and their growth rate will reduce dramatically. Another common sign of insufficient light is color loss. Many plants lose their bright hues over time, becoming much duller and darker than nature intended.
Wintertime presents further light problems with its dramatically lessened daylight hours. You’ll find that even plants that were perfectly content on a sunny windowsill in summer time can falter in their search for light in winter.
This is when using indoor grow lights are the only option. Grow lights provide adequate amounts of the right sort of light and will keep your plants in prime condition. They’ll be bushy in structure, bright in color, and naturally beautiful. Today we’ll take a journey through the somewhat confusing science of full spectrum LED grow lights in a bid to understand exactly what benefits they bring to the houseplant enthusiast.
So, Why Use Grow Lights?
Grow lights provide a synthetic light that is the equivalent of sunlight. The leaves and petals of your plants act as solar panels, absorbing photosynthetic light from the sun. Unfortunately, normal indoor light isn’t sufficient to replace sunlight, but grow lights can actually mimic the sun’s photosynthetic spectrum. As a result, they’ll keep your plants happy throughout the year.
But what sort of grow lights should you use and what are the differences between them?
Well, this can be a daunting situation, as there are many different types available. Providing 12 hours of supplemental light will keep your houseplants happy throughout the dull winter months. This will keep their colors strong and their growth rate healthy. Let’s take a good look at the several types of indoor grow lights available, from traditional florescent tubes to full spectrum LED grow lights
Types of Lamps
1. H.I.D.: High Intensity Discharge
These are the lights most used in commercial growing operations. They provide the highest amounts of light and heat, but also consume the most energy and are therefore the most expensive to run.
2. H.P.S.: High Pressure Sodium Lamps
Part of the H.I.D. family of bulbs and often used for street lighting and industrial operations. These are pretty energy efficient and have a long lifespan. The H.I.D. bulb emits an amber-orange light, much like an autumn sunset.
3. M.H.: Metal Halide Lamps
Also part of the H.I.D. bulb family, these are similar to the H.P.s. Both lamps are capable of producing a high quality of light output, but in different parts of the color spectrum. Metal Halide lamps produce white light and are recognized as the best lights for strong vegetative growth. Ideal for leafy vegetables.
4. Full Spectrum L.E.D. Lights: Light Emitting Diodes
These release P.A.R. light which stands for photo synthetically active radiation. These offer greater efficiency and overall, better results.
Full Spectrum L.E.D. lights can now generate light over a wide spectrum, mimicking the ultraviolet rays from the sun. A bonus in using these is they precisely pinpoint the ideal photosynthetic spectrum needed by plants for peak chlorophyll absorbance. In addition, they’re noise-free, unlike florescent lighting.
While all light will help your plants grow strong and healthy, full spectrum led grow lights are almost as powerful as sunlight. This makes them one of the most popular and powerful lighting choices on the market today.
They’re also pretty energy efficient and low cost in the long term. The running costs of using these lights is less than the H.I.D., or any alternative lighting system. This in turn saves energy and plays its own part in saving the planet. They’re sufficient for a varied growing collection, and because they do not convey too much heat, they allow you to place different types of plants in one location, never scorching tender plants.
5. White L.E.D Lights
These can’t generate light over a wide spectrum but have soft white bands of light, rather than the red and blue, or the Full Spectrum L.E.D.’s ultraviolet light. They can’t pinpoint the plant’s perfect growing spectrum, but are more cost effective. As a result, they’re ideal for those who would rather not have colored lights at home.
Using white lights within the Full Spectrum L.E.D.s, however, ensures that plants receive all the photosynthetically active radiation needed to optimize plant growth. This will improve crop yields and enhance plant health.
Why use Full Spectrum LED Grow Lights?
NASA research has determined that L.E.D. Full Spectrum Lights are the best source of lighting for indoor grown plants, both on Earth and in space. Let’s take a look at how they came to this conclusion.
- Less heat is omitted, so no plants are damaged
- Great for use in small spaces—L.E.D.s are available in a large range of shapes and sizes
- You can choose monochromatic lights (lights on one wavelength), or lights on different wavelengths
- This modern lighting doesn’t need ballasts like florescent tube lighting or some of the older grow lights
NASA also launched research into which light wavelengths were most beneficial to a plant’s growth cycle. It was determined that red and blue offer the best support for growing plants indoors, aiding photosynthesis to take place. In short, photosynthesis is the process plants use to transform light into the energy they need for growing and flowering.
Taking into account these results, further exploratory tests were carried out to pinpoint the specific effect of different light wavelengths on indoor grown plant specimens. Before I explain any further, let’s have a quick lesson on light and how it’s measured.
The human eye is capable of seeing visible light in the electromagnetic spectrum. This spectrum is measured in nanometers, (nm), with visible light having wavelengths ranging from 280 – 770 nanometers. Infrared, radio waves, x-rays, gamma rays etc., are all wavelengths outside of the visible spectrum of colors we can see.
As an example, infrared light is somewhere near the 700-nanometer range. In short, Nanometers are just a unit of length, much like meters or cm, to measure the wavelength of visible light.
Now, let’s take a look at the effects of light wavelengths on plant growth.
Red Light: 630–660 nm
- Essential for stem growth and leaf expansion
- Regulates seed germination, flowering, and dormancy periods
Blue Light: 400–520 nm
- Affects leaf thickness and a plant’s chlorophyll content
- Needs to be carefully mixed with other light spectra for healthy plant growth as over-exposure of blue light alone (in this wavelength) can cause stunted growth in certain plant species
Green Light: 500–600 nm
- Studies have shown light in this wavelength penetrates through a plant’s thick top canopies to support leaves in the lower canopies
Infrared Light: 720–740 nm
- This light wavelength also passes through a plant’s dense upper canopies, supporting the growth of leaves lower down on the plant
- When exposed to infrared light, the time a plant needs to flower is reduced
- Studies have shown larger leaves are produced under infrared light
Now we know that using L.E.D. lights is proven to be the way forward; it is also important to think about what plant groups you’ll be growing.
Pretty much all of the lighting products available, work towards the same aim: getting plants to the flowering stage. That said, some are better suited to certain crops than others. For example, some lights need only be used for the vegetative growing periods and flowering stages of a plant’s life and not the entire time.
Others have separate modes for each growth phase, even allowing you to alter the light spectrum to ensure the correct spectrum of light is used for each specific growth phase of your plants. This is a relatively new development within the grow light industry. Literally tailor-made technology!
Indeed, full spectrum LED grow light technology has definitely moved on. Not only has this taken the guesswork out of manual grow lights, it has set a precedent for the whole industry.
How do they shape up?
Shape is another important aspect that needs to be thought about before you invest. Knowing where you’re going to be growing your plants gives a better idea of what to look for when it comes to lighting. Full spectrum L.E.D. grow lights come in all shapes and sizes, making them a suitable choice for all areas. There are lighting bars, panels, bulbs, saucers etc.
Please do your research before you go to buy.
When it comes to L.E.D. grow light systems, bigger does not always translate to a bigger area coverage, like it does in regular H.I.D., H.P.S. and M.H. lights. However, rather than going into the very complex world of photosynthetic photon flux density, I’ll use wattage as a means to determine the required area of light coverage.
As a rule, you’ll find that a standard L.E.D. Full-Spectrum Grow Light must use over 32 watts per square foot, but optimizes from 50–80 watts per square foot of growing space.
As a starting point, I’ve listed a quick guide for a given growing area.
Measurements in Feet:
- 1 x 1 = 32 watts
- 2 x 2 = 128 watts
- 3 x 3 = 288 watts
- 4 x 4 = 512 watts
- 6 x 6 = 1152 watts
This is just a rough guide, but gives you an idea of what you’ll need for your growing space.
Further Aspects to Keep in Mind with Full Spectrum LED Grow Lights
Firstly, due to the initial investment, I recommend using a company to supply your Full Spectrum L.E.D. Grow-light systems that has an established record of success, with glowing customer reviews. You also want to deal with a company that has been in the business for a reasonable amount of time and really know what they’re talking about.
Choose a Trusted Manufacturer
As with your grow light suppliers, the manufacturer you choose should be trusted to produce a quality product. There are many within the U.S. that make some of the highest quality L.E.D.s out there. Look out for Osram, LEDengin and CREE—all of which have a super reputation within the industry. Also take a look at the warranty they offer and the returns policy, should you need to use it.
Ease of Use
After taking the time to choose the correct sized light systems for you, your chosen Full Spectrum L.E.D. Grow lights need to be easy to initially install and easy to adjust. In many of the best systems, you can easily adjust the height in accordance with what you’re growing. This is not an aspect to overlook.
Florescent Tube Lighting
This is the most traditional and cheapest lighting option. A popular choice for small to medium plant collections and handy for starting seedlings off. In the short term, it is a fairly cost-effective choice, but bulbs do have a rather short lifespan.
Choosing a florescent tube bulb with a diameter of 1.5 inches, (3.81 cm), is a reasonable substitute for sunlight. This will generate light over an area of 4 ft x 4 ft, (1.2 m x 1.2 m), create a lot of heat, and run at anything between 400 to 1000 watts.
A downside of these lamps is that they don’t provide the exact light which is of great benefit to your plants and whilst running, they do produce a buzzing sound. A lot of what they provide is actually heat, as noted above, and not essential light. An estimated 80% of what they omit is heat, which can scorch and harm tender plants if placed too close.
Lumens = Light Output
Florescent tube lighting is measured in lumens and this equals the amount of light output. Lumens = the measurement of total visible light to the human eye from a lamp or light source. The higher the lumen rating, the brighter the lamp will appear.
To give an equivalent:
- Full daylight has a rating of 9300 to 2300 lumen per foot squared
- Direct sunlight has a rating of 3000 to 12,100 lumen per foot squared
With grow lamps, we aim to replicate a similar lumen measurement to that of daylight.
3 Main Types
There are three main types of suitable traditional florescent tubes that are still used today by avid indoor gardeners: the T12, T8, and T5.
The T12 is the common favorite, generating between 1980 and 3400 lumens. This is an affordable but soon to be discontinued choice, with less efficiency that the alternative florescent tubes available. The T8 generates between 2850 and 3400 lumen,s and the newly available T5, has a brighter light output and much better efficiency than any of its predecessors. The “High Output T5” bulb generates a huge 5000 lumen per square foot and runs at only 54 watts.
This is why full-spectrum L.E.D. lighting seems to have overtaken the traditional incandescent bulbs. A huge increase in home growers has pushed technology to catch up with demand, bringing us a selection of full-spectrum L.E.D. grow lights that pinpoint the exact light needs of plants and deliver results every time.
Many of us choose to use a grow light system to enhance the effects good light has on our plants. This has resulted in the huge choice of grow light options available. Opting for full spectrum LED grow lights will assure your lights don’t overheat or damage your tender plants
- You’ll need to be aware of energy efficiency, choosing products that won’t be too expensive to run for at least 6 hours per day, and those that have a greater life expectancy
- Choose a wide angle to allow for even lighting and indirect lighting
As a final thought, remember that like all plants, even succulents and cacti still require darkness hours for a healthy growing cycle. Light is vital, but darkness is necessary too.