Full Spectrum LED Grow Lights 2018: Guide and Reviews
Whether you choose to grow hydroponically or with traditional soil, if you are growing marijuana indoors you will need a grow light. Plants need sunlight to make food, so indoor grow lights are there to replicate the sun’s rays and help your plants photosynthesize.
LED grow lights are great for indoor use as they are full spectrum. We will explain exactly what full spectrum means and why it is important in our guide, as well as review four budget-friendly LED grow lights to give you an overview of what is currently on the market.
What does “full spectrum” mean?
A full spectrum grow light is one that emits every wavelength of light that a plant needs to photosynthesize. Grow lights focus specifically on the wavelengths of light that plants are most capable of using, which is within a range of wavelengths between 390nm and 700nm.
When growing plants indoors, you will need to be aware of two light spectra: the absorption spectrum (light wavelengths that plants can absorb); and the action spectrum (light wavelengths that plants can use to photosynthesize).
A good full spectrum grow light will emit all light wavelengths that plants can absorb, but give off more of the wavelengths that plants can actually use to make their food.
However, not all full spectrum grow lights produce exactly the same spectrum. They are all built on the same basic principle – that they should emit wavelengths that the plants can actively use to grow – but lights from different manufacturers will differ slightly. This is because different companies use different kinds of LEDs and will arrange the bulbs differently on the panel. Some grow lights even have extra infrared and/or ultraviolet LEDs too.
Each LED grow light is built slightly differently, with some lights that are only designed for the vegetative or flowering stages of cannabis plant growth, whilst others are built to suit the entire grow cycle. Some cannabis strains even have different light requirements, so it can be tricky to choose the right LED grow light for you.
Once you know what you want your end product to be, then you can tailor your light spectrum needs to that. Whether you want your bud to have a great flavour, to be high in THC or CBD, or you want to make oil or shatter, you will need to choose a grow light that emits the right light spectrum ratio for your plants.
Grow lights that have an adjustable spectrum to mimic how the sun’s rays change throughout days and seasons are really useful, as the settings can be altered to optimize certain light wavelengths depending on what your plants need. Before you start growing, research your cannabis strain to make sure you are optimizing its grow environment to get the best yield possible.
PAR and other important light wavelengths
Photosynthetically Active Radiation (PAR) are the light wavelengths that plants can actually use to photosynthesize. The higher the PAR value a grow light has, the better. At either end of the PAR spectrum, there are light wavelengths that plants don’t actually use for photosynthesis but are still important for how the cannabis plants grow.
Ultraviolet light causes a larger production of trichomes, cannabinoids and terpenes by provoking a range of defence mechanisms in cannabis plants; infrared light aids budding, yield and trichome production by speeding up photosynthesis via the Emerson Effect.
LED bulbs can’t actually produce white light because there are no white diodes. There are two ways LEDs can produce white light (as it appears to the human eye). The first is to use chips with equal amounts of blue, red and green diodes, which together produce white light. The second (and far more common) way is to use blue LEDs coated with phosphor.
White light isn’t hugely important to plants. It is just all the light wavelengths combined, which appears white to the human eye. It can, however, be useful, as it shows the plants in their true colour (rather than in a red or purple hue) and makes it easier to spot any potential discolouration of the leaves or stems.
This is to do with how many photons fall onto your plants, and how far below the canopy they can penetrate (rather than how bright the light appears to us). Usually, light intensity is measured by the wattage of the bulbs, but for LED lights this isn’t strictly true. An LED light marked as 300W means that it can replace a 300W HID light. However, LEDs are much more energy efficient, so an LED light marked as 300W will emit the same amount and quality of light, but will actually draw a lot less than 300W from the plug socket, making it far more efficient than its HID equivalent.
Marijuana plants need different amounts and intensities of light depending on which growth stage they are in. For the vegetative stage, plants need around 18 hours of light and 6 hours of darkness, but when they are flowering they need 12 hours of light and 12 hours of darkness.
Choosing the right light for growing marijuana
One way to make sure you pick the right light is to calculate one 32W unit per square foot of growing space. So for example, if you had a growing space of about 16 square feet, you would need a grow light of around 550W. Make sure you know what your weed strain requires for each of its growth stages too, so you can meet its needs and get a higher yield.
When marijuana plants are in the vegetative stage, they are exposed to light for more hours that when they are flowering. To make the most of the reduced hours of light in the flowering stage, most growers will lower their grow light to be closer to the canopy of their plants, thereby maximising the shorter light exposure, but also decreasing the area the light can reach. It is therefore important to choose a grow light that will still cover all your plants, even when lowered for the flowering stage.
Now let’s move on to the reviews.
Viparspectra 1200W Full Spectrum LED Grow Light
At 1200W this is a very high power grow light, but is still good value compared to other grow lights with a similar wattage. It can replace a 1200W HID lamp, but actually requires a lot less electricity, using on average just 524W, helping you save on utility bills. The Viparspectra also comes with a 3-year warranty in case anything needs replacing.
With the Viparspectra you can adjust the light spectrum according to your plants’ needs, helping you control plant growth during the vegetative and flowering stages. It also has aluminium heat sinks and a built-in cooling system of six fans, which prevents your plants from drying up and also makes this grow light highly durable.
This LED grow light is not one of the cheapest around, but it is extremely powerful, flexible and durable. It is highly recommendable if you have a bit more cash to spend.
Bestva 2000W Double Chips Full Spectrum LED Grow Light
The Bestva 2000W grow light has something called Chips On Board (COB) technology, which is an additional way of keeping the light cool. It has strategically placed solder points so as not to require too many, as the more solder points there are, the hotter the lamp will run.
This grow light has great durability with a lifespan of up to 50,000 hours and a 3-year warranty, and at a height of 6.5 feet it can cover about four square feet of ground. It is also highly energy efficient, only drawing about 390W to produce the same amount of light as an equivalent HID lamp.
Again, this is not one of the cheapest LED grow lights around, but it is highly worth spending the extra money if you have it as you will definitely be thankful in the long run.
Galaxyhydro 300W Full Spectrum LED Grow Light
This sturdy growlight measures 12x8x2 inches and weighs about 5 pounds, and it comes with a 2-year warranty. It can replace a 300W HID lamp whilst only needing 140W to produce the same quality of light, making it energy efficient and thus environmentally friendly. It doesn’t have COB technology, but it does have integrated fans to make sure it doesn’t overheat or burn your plants. It also has some infrared bulbs to help speed up photosynthesis.
The Galaxyhydro is overall a great LED grow light, with plenty of blue and red chips to provide your plants with all the different light they need to grow healthy and strong.
Best World 300W Double Chips Full Spectrum LED Grow Light
This is a budget-friendly grow light, with the usual LED lifespan of up to 50,000 hours and a one-year warranty. It only covers a small area (about two square feet during flowering) so it would suit a grower who only wants to grow a couple of plants. This light is also better suited to the flowering stage, as it emits more red light (82 red bulbs, 12 blue and 6 white).
If you are sticking to a tight budget, this light would make a great purchase. However, if you can spend a little more do, because it will be worth it later on when your plants grow faster and your bud yield is higher.
Hopefully you now understand a little more about full spectrum LED grow lights. Good luck with finding one that suits your needs and the needs of your cannabis strain. Happy growing!