You are hereWhich Grow Light? | Marijuana Grow Light Guide
Which Grow Light? | Marijuana Grow Light Guide
by Nebula Haze
Which Grow Lights Are Right For Me?
The marijuana grow lights you choose are definitely not the only factor that will affect your growing success and yields.
But... when all other factors are equal, the general rule for growing marijuana is that more light = more buds.
When I'm talking about "more light," I mean the light that is actually reaching your plant. Now of course, increasing brightness will not increase yields if your cannabis plant is sick or unhealthy - and even with healthy cannabis plants you only get benefits up to a point (at high enough levels of brightness, your cannabis plants simply can not use any more light). Yet adding more brightness with better grow lights (especially when used along with cannabis training techniques) can be one of the most straightforward ways to increase yields when growing indoors.
Do you need to upgrade your grow lights or stick with what you've already got? Learn more here: http://www.growweedeasy.com/grow-light-upgrade-guide
How do I increase yields indoors? http://www.growweedeasy.com/5-tips-increase-yields-growing-indoors
For those interested in getting cannabis grow lights for the first time, the info on this page may come in handy while you're trying to choose the best marijuana grow light for your setup and needs.
How to Compare Marijuana Grow Lights
Skip right to the cannabis grow light section you want to learn about...
I already have grow lights, but I want to Upgrade...
Which Grow Lights Do You Have Now? (view the upgrade guide!)
Are you ready to get starting growing marijuana with indoor grow lights?
Marijuana plants are not like your average indoor houseplant.
They live out their whole lives (seed to harvest) in just one year; they need to get a lot of light in order to make enough energy to grow big and produce buds (marijuana flowers).
Generally, you will need special types of lighting (grow lights) to grow marijuana, though some regular house lights can work too, if you know which ones work.
Please note: Incandescent light bulbs are NOT suitable for growing marijuana!
Of course, if you plan on growing marijuana outdoors, the sun is generally all the light you need to grow your own weed. When growing outdoors, your marijuana needs to grow in a sunny spot with plenty of direct sunlight throughout the whole day. For best results, plants should get strong sunlight for 8+ hours each day.
For indoor and outdoor growers, it's important to learn about the importance of light to a photoperiod plant like cannabis.
Cannabis is a "short-day plant," which means that cannabis plants don't start making buds until their "days" become short enough. Plants like cannabis can actually sense periods of darkness, and use the length of darkness each night as a sort of internal clock telling the plant when to start flowering. In the wild, cannabis plant need to start flowering in summer so that buds are produced and seeds are dropped before winter arrives and kills the plant.
Darkness is important for making buds. Cannabis is a "photoperiod" plant, which means the amount of uninterrupted darkness experienced by the plant each day determines when the plant starts starts flowering (making buds). Most cannabis plants won't start flowering until they get long (12+ hours) nights. In order to make buds properly, cannabis plants need to continue receiving 12+ hours of total darkness each day until harvest.
Note: Rules about darkness do not apply to auto-flowering strains. Auto-flowering (or Ruderalis) plants are a special type of cannabis that can only grow from seed. Auto-flowering strains don't pay attention to photoperiods. In fact, auto-flowering plants will reliably be ready to harvest in about 3 months (give or take a month depending on the strain) no matter how much darkness received each night. Because of these short lives, auto-flowering plants tend to stay small.
It is very unlikely you will ever run into auto-flowering seeds unless you order auto-flowering seeds from a seed bank. Even though you can't tell the difference between auto-flowering and photoperiod buds (the buds are the same), auto-flowering is a recessive trait, and usually doesn't show up in cannabis seeds unless someone specifically bred for it. So far we haven't heard any reports of people finding seeds that ended up being auto-flowering. If you have unknown seeds, assume they are photoperiod seeds.
The factor that determines when photoperiod cannabis plants start making bud is the photoperiod, or the length of time the plant receives darkness each day.
Outdoors, the sun is in charge of flowering (when your plants start budding). (unless you have an auto-flowering plant). When the nights start getting longer towards late summer and autumn, your cannabis plants naturally start flowering as long as their nights aren't interrupted by light.
Indoors, you are in control of flowering (when your plant starts budding). As a grower, you do this by adjusting the plant's daily light schedule, usually by hooking up your grow lighs to an automatic timer. These timers can be plugged into any outlet and will turn your grow lights on and off for you (like an automated light switch).
How much light should I give my plants each day? http://www.growweedeasy.com/how-much-light
Some strains of cannabis are "auto-flowering" which means that they ignore the length of the photoperiod, but these strains are rare to come across unless you specifically buy auto-flowering cannabis seeds. What are autoflowering strains? http://growweedeasy.com/autoflowering
The color spectrum of the light your plants get will also have a small effect on their vegetative and flowering stages. Light that's closer to the blue spectrum simulates Spring/Summer while light in the red spectrum simulates sunlight from the Fall/Winter. As long as you buy a grow light that is meant for growing cannabis (like all the ones listed on this page), your color spectrum will be close enough to get results. Even if you provide the wrong color of light at the wrong time, your plants will still grow and produce buds. While it's a good idea to get the right color light for each growing stage, the color spectrum of your grow light has a small effect on your plant's development compared to the photoperiod (how long the plants gets light and darkness each day).
- Wait! I'm Still Confused About Photoperiods. How Much Light Does My Plant Need To Start Making Buds?
- Tell Me More About the Effect of Light Color Spectrum on Growing Marijuana
- I want to upgrade my current grow lights, please guide me!
The big advantage of using indoor growlights is they effectively control all aspects of your plant's light.
Because of this total control over light when growing indoors, indoor growers can provide consistent growing conditions, including light, humidity, temperature, watering, etc. Outdoor growers are much more dependent on the local climate and weather to provide what's needed for their plants..
The most common types of grow lights for cannabis are High Intensity Discharge (HID) lights.
HID Grow Lights
- Metal Halide (MH)
- High Pressure Sodium (HPS)
HID grow lights are powerful and proven to provide great yields.
What size HID grow lights are right for my space? http://www.growweedeasy.com/mh-hps-upgrade-guide
WIth HID lights, you will tend to get the best yields of any other grow light compared to the electricity used. But with bigger lights, you will generally also have to install some sort of exhaust system to properly exhaust out all the extra heat. For growers willing to take the steps needed for MH/HPS grow lights, the results are worth it!
You can also grow marijuana plants using Compact Florescent Lights (CFLs) and LED grow lights. These types of lights are generally smaller than HID lights. Neither perform as well as an HPS light for yield/watts.
CFLs are well-suited to very short grow spaces, and LEDs are believed to produce higher-quality bud.
Each type of light system has their pros and cons, but you will need to find the one that fits your budget, grow area, and grow style.
Here's a basic breakdown of the most common marijuana grow lights by grow style..
- Cheap to set up & maintain - great if you just want to "Dip Your Feet" and try growing out, or if you have a small starting budget
- Can be a stealthy option for small or micro grows - Low heat, low electricity
- Compatible with a very short grow area, even inside a bucket
- If you upgrade to different grow lights later, you'll still be able to use these lights for clones or young plants in the vegetative stage
- CFLs are one of the least efficient types of grow lights (considering light produced/electricity used)
- Can only grow small plants (not suited to big grows)
- Tends to get smaller yields than other grow lights
- Can be tough to control height (plants need to be kept short under these lights)
For a cheap, small grow of 1-2 plants. For someone who doesn't have a lot of money to spend. For a grower with a short grow area. For a grower who just wants to give growing a try without investing a lot to get started.
Feel free to check out this tutorial about how to start growing marijana with CFLs for less than $300.
Learn More About CFLs vs MH/HPS
Deluxe Grow Lights
MH / HPS Combo (HID Grow Lights)
- Grow many plants indoors
- Very easy to maintain
- Comes in big and small sizes to fit the need of many grow spaces. Learn if your grow space is big enough to use MH/HPS lights
- HIDs are efficient grow lights for cannabis; MH/HPS tends to produce the bigger yields than other grow lights considering the amount of electricity used
- The golden standard for growing cannabis indoors - HIDs are the most tried-and-tested grow lights, having been used for growing cannabis for decades
- Know what to expect - many people find HIDs to be the most intuitive grow light, and there are lots of straightforward grow guides for growing cannabis with MH/HPS grow lights
- These bulbs cannot be plugged into a regular light socket; they need a special hood and ballast (usually sold together) - Teach Me More: http://www.growweedeasy.com/hps-grow-lights-setup
- Like any other high-wattage grow light, bigger HID grow lights often need an exhuast system to vent out heat - Learn how to make a cheap, stealthy exhaust for your MH/HPS lights: http://www.growweedeasy.com/hps-exhaust
- Can be expensive to get the grow lights & set up the grow area
If you have a bit of money to get started, a grow space or closet that no one will see, and the willingness to put a little more time and effort into setting up, than HPS (High Pressure Sodium) lights, or a combination of Metal Halide and HPS lights, are your best choice.
Both MH and HPS lights can be used for the whole grow cycle and work well. But you will get even better results when you use both types of HID lights - MH and HPS.
Use your Metal Halide bulb for the vegetative stage, and the HPS bulb for the flowering stage. This combination of grow lights closely mimics the sun's natural light during the different seasons, and is the most tried-and-tested grow light combination for growing marijuana. Many modern ballasts come with the ability to support both kinds of bulbs.
"Mad Scientist" Grow Lights
- Many growers report LEDs produce greater resin production and better taste/smell than other grow lights. The type of light produced by LEDs may cause cannabis to produce more trichomes (glitter) and terpenoids (smell) in the flowering stage.
- LED grow lights are efficient - they produce a lot of light for the amount of electricity used
- LED grow lights continue to get better for growing cannabis - LEDs are relatively new. and cannabis yields are going up while prices are coming down
- Most LEDs come with a built-in fan to disperse heat up and away from the plants
- LEDs can be plugged directly into the wall - no need for a separate ballast
- High initial cost
- Don't believe all the crazy marketing hype about LEDs - if a claim sounds too good to be true, it probably is! Some unscrupulous retailers are trying to make a quick buck by selling poorly designed or untested LEDs to unsuspecting growers, often making outrageous claims.
- Lower yields/watt than an HPS grow light
- LEDs, like all grow lights, produce heat. With bigger models (using lots of LED chips) you will need to vent hot air outside, even if the LED has a built-in fan.
- Poorly designed LEDs can cause bleaching, crispy leaves, spots and other cannabis growing problems. This can also happen if LEDs are kept too close to your plants. Always buy LEDs from a trusted source that has tested their models on real cannabis plants! Also make sure the seller tells you how far to keep the LEDs from the tops of your plants.
For the advanced grower who wants to use the most cutting edge technology while achieving the highest quality buds possible, LED grow lights may be the best choice for your next cannabis grow.
Only purchase LEDs from a trusted source!
It's important you choose a LED panel from a company which have tested their panals on real cannabis plants. It's recommended you purchase your lights from a company with at least a 1-year guarantee
Each model is different. Don't ask a friend or fellow grower about how to use your LED panel - make sure you get information directly from the manufacturer about how to use your panel. Always find out how far to keep the LEDs from the top of your plants
Supplemental Grow Lights
(easily add more light to your grow)
- Low heat produced & electricity used for small plants or clones
- Great for filling in shadowy parts of the plant with more light, or can be used as side lighting
- Great choice for seedlings, clones, and small vegetating plants
If you are in a situation where you need a bit more light in a specific place, but don't want to significantly affect the temperature or your electricity bill, CFLs, flourescent lighting, or induction lights can be "plugged in" around your plant to give that extra light you need, to take your yields to the next level.
They are also a great choice for smaller plants, seedlings and clones, where a little light goes a long way.
And Now For The Complete Marijuana Grow Light Breakdown...
The two main types of High Intensity Discharge (HID) lights used for growing marijuana are Metal Halide and High Pressure Sodium lights.
MH / HPS lights are generally considered the golden standard for growing marijuana.
HID lights will help you produce great yields. Many growers believe that the Metal Halide/HPS grow light combination will acheive the best cannabis yields, though other types of grow lights can be close contenders.
Though HPS or MH/HPS grow lights consistently producte great yields, they also produce heat that needs to be vented out of small grow spaces. Therefore you will most likely have to set up fans and ducting to properly vent out all the heat. Some growers even use these lights to help heat up their homes in the winter.
Metal Halide (MH) lights produce light with a lot of blue and white in the color spectrum. This mimics the light produced by the sun in the Spring/Summer, which makes it most suitable for use during the vegetative stage of your marijuana plants.
Metal Halide (MH) for the Vegetative Stage
Many growers use Metal Halide lights for the vegetative stage of their marijuana plants.
Young marijuana plants explode with green, healthy growth when exposed to MH grow lights.
Metal Halide grow lights can be used for the entire lifespan of a marijuana plant, but if you must choose just one, most growers choose to use HPS for the whole grow.
Metal Halide bulbs produce light in the blue spectrum, which mimics the sunlight during the Spring and Summer, and gives young vegetating plants exactly what they need.
This blue-tinted light causes your plants to grow fast vegetative growth (stems, branches, and leaves only), and encourages young plants to grow short and bushy.
It's possible to skip the Metal Halide bulb and use a High Pressure Sodium (HPS) bulb for your whole grow. If you can only afford one bulb and have to choose between MH and HPS, always choose HPS. Best results are achieved with both MH and HPS light during the grow.
HPS grow lights produce light that is perfect for use during the flowering stage of your marijuana plants. The light that an HPS emits will appear amber/yellow or even pinkish. HPS bulbs are often used in street lights or to light huge areas like stadiums because they are very efficient.
High Pressure Sodium (HPS) for the Flowering Stage
Most growers who started out with MH switch to High Pressure Sodium bulbs for the flowering stage.
This takes advantage of the optimal light spectrum needed by your plants during the flowering stage to produce big, potent buds.
High Pressure Sodium grow lights produce a pinkish yellow light with lots of light in the red/orange spectrum.
This yellowish light causes plants to stretch upwards, while also promoting bud growth. Using HPS grow lights in the flowering stage tends to produce the biggest yields/electricty than any other type of grow light.
Choosing your MH or HPS Grow Lights
If it's your first time growing with an MH or HPS grow light, it may be easier to buy your bulb(s), ballast, and hood (reflector) together as a set. But while it may seem confusing at first, it's actually easy to match bulbs, ballasts, and hoods together.
The most important thing to remember is that the type of bulb and the type of ballast always need to match each other. In practice, this is really easy and clear; you just match up the numbers. The link below will walk you through everything.
If you must choose just one type of HID light (for some reason you can't get both MH and HPS), most growers choose to use HPS lights from beginning to end of your marijuana plant's life cycle. Just be gentle during the seedling stage! HPS lights also tend to cause young vegetative marijuana plants to stretch, so you may want to employ some growth control methods so your plants grows exactly the way you want..
Of all the different types of HPS lights, the 600W HPS light is the most efficient as far as how much light they produce for how much electricity used.
As far as maintenance and setup, Metal Halide and High Pressure Sodium bulbs are pretty much the same. They are both very easy and straightforward.
All HID lights (Metal Halide or HPS) require that you have a...
- Ballast (which usually plugs into a standard power socket)
- Hood (reflector)
- Exhaust (optional but important - usually a fan plus ducting to vent out heat)
These lights need a ballast to control the flow of electricity to the lamp, because these bulbs can't just be screwed into any sort of regular light socket. The ballast is plugged into the wall, and your light is plugged into the ballast, just like you have a ballast for your laptop.
The hood is used to reflect light down onto the plants, and the nice ones have features to help you control and properly exhaust your heat.
HID lights produce heat when in use, and almost all growers should get some sort of exhaust or ventilation system.
An air-cooled hood allows you to easily set up a fan to move all the hot air away from the lights (and out a window or other direct connection to the outside).
If you feel overwhelmed, it can be easier to buy the whole HID system together as a kit instead of buying all the pieces separately. There's nothing more frustrating (and potentially dangerous) than trying to fit parts together that just don't quite work! But it's easy to get all the parts separately, too.
By the whole system I mean the bulb, ballast and hood (reflector).
You can purchase a system that suits all your needs, and as long as you match all the numbers, you can be confident that everything will fit together properly.
I strongly recommend against buying a used light system to save a few bucks.
Some growers don't take good care of their lights. You don't always know what you're getting, and there's no guarantee.
Additionally, after HID bulbs have been used for a while, they will start to consume more electricity while also producing less light. When this happens, you will need to replace the bulbs.
Why start with someone else's half-used equipment?
There are many cheap options available for new, high-quality equipment, but you need to know the right places to look.
These lights are commonly sold at home improvement stores, and even in grocery stores.
Many people don't realize that these regular household light bulbs actually provide a spectrum of light that your cannabis plants can use to grow!
You will need two or three 42w(150w incandescent equivalent) CFLs per plant to start.
These lights are easily found at stores such as Home Depot and Walmart, or that can be purchased online.
CFL grow light upgrade guide - Get the Right Bulbs
You can get lower or higher wattage bulbs, but I like bulbs close to the 40w range because they produce a lot of light, but are still a small, manageable size.
Some of the bigger CFL bulbs (especially the ones over 80W) start to produce a lot of heat, and are difficult to aim the light at your plants. If you're going to grow a lot of plants, or really big plants, you will probably want to upgrade to an MH/HPS combo as CFLs are really only suitable for a small grow of 1-2 marijuana plants.
By the time your plants have started flowering, you will likely need to get more CFL bulbs per each plant to fill in any 'shadowed areas' up to maybe 2 or 3 more CFL bulbs per small plant. More for bigger plants.
Basically, when you're deciding how many lights to get, you want to focus on making sure the plant has 'full coverage' more than you really care about a certain number of lights or watts.
If the plant is brightly lit wherever there are green leaves, then you're good. If there are any 'shadowed' areas, then you know that your plant needs more lights.
It's optimal to use 'daylight' (6500k) colored bulbs for the vegetative stage and 'soft white' (2700k) colored bulbs for flowering (though you can use either kind during either stage and your plant will come out fine). I like to use a mix to make sure my plants get a full spectrum of light.
If you must choose just one "color" of CFL bulb, it's best to go with all Soft White (2700K) as this works fine in the vegetative stage and does a great job to promote budding in the flowering stage.
I recommend getting some heavy duty clamp light sockets which you can use to power your light bulbs.
These light sockets are able to clamp to most anything and they come with a reflector for your lights.
You might be surprised at how annoying it is to try to find a way to make a 6 foot cord work.
To maximize the light your plants are getting, you can use a light socket extender and a twin light socket adapter to fit two lights per each clamp light socket (without the extender, they probably won't fit).
Setting up 2-4 lights per socket can often be cheaper than buying an individual light socket for each light, especially if you buy online. It also is really convenient for arranging around your plant.
A CFL grow light setup by grower iskraiskra
(click pic for closeup)
In recent years, we've seen the creation of new high-light-output versions of fluorescent grow lights which can actually be used through the entire vegetative stage.
Some growers even use fluroescent grow lights such as the T5 successfully to flower their plants (if the plants are kept short/small enough through growth control methods).
In general, I recommend changing to stronger grow lights for the flowering stage. Unless you keep your plants very small, they will need more light to produce buds than a fluorescent light can usually produce. If you're in a dire situation where your plants have grown too big and you can't afford to get a different type of light, you can supplement your fluorescent tubes with additional light, for example you could supplement their light with a few CFL(compact fluorescent light) bulbs wherever you notice any "shadowy" areas. This is only a minor fix - the real fix is to grow very short plants or upgrade to a bigger light for the flowering stage.
The biggest problem with fluorescent tubing is that the light that they give off is only useful for about a foot or so.
Any part of the plant that is further away then 1-2 feet from the fluorescent grow lights is not getting an optimum amount of light, especially in the flowering stage when plants need a lot of light to produce buds.
With the new high output lights such as the T5, fluorescent lights can be used until the plants are about 24 inches tall, which is just enough to grow a very short plant through to the flowering stage when you control your marijuana plant's growth through the vegetative stage.
The great thing about fluorescent grow lights is that they don't get very hot, and they can usually be kept 1-4 inches from the tops of the plants at all times without having to worry about burning your cannabis leaves or buds.
The other great thing about fluorescent lights is that they are energy efficient, and with a few small wattage lights, they won't make a huge mark on your electricity bill.
There are many different levels of fluorescent grow lights including the T5, the T8 and the T12. I strongly suggest sticking with the T5 style of fluorescent grow lights for cannabis because they give off the most amount of light for the size, and are specifically designed to be able to support taller plants up to 24 inches.
For optimal results, for vegetative growth choose fluorescent light bulbs that are labeled either as "Cool White" or "Cool" colored (also labeled as "6500k" colored).
For flowering, choose bulbs that are "Warm White" or "Soft White" colored (usually labeled as "2500K" or "3000K").
However, you can use either type of lights during either stage and still get good results. I have also heard of people using "Daylight" (5000K) bulbs with success.
If possible, opt for bulbs labeled as "High Output." This ensures that you're getting the most lumens (light) from your bulbs. But any T5 bulbs will work - hundreds of cannabis growers have the harvests to prove it!
You may or may not know about the LED grow light craze which is common among cutting-edge marijuana growers.
LED grow lights are efficient, have built-in fans, produce more trichomes, can be plugged directly in a wall outlet, and use advanced technology - so there's good reason for all the attention.
Today, I'll be answering the following questions:
- What are LED grow lights?
- Why is there so much controversy about LED grow lights?
- What are the benefits of LEDs?
- Which companies, if any, have the best LED grow lights (specifically for growing marijuana)?
Grow lights made of light emitting diodes are commonly known as LEDs. You may have seen ads for these lights, which often resemble UFOs, and claim to be the growing technology of the future.
First invented in 1927, no one could find any practical use for these tiny lights until 1962, when LEDs first hit the scene in 1962 as glowing red indicators on electronics.
After that, LED development has proceeded rapidly.
LEDs, which were originally tiny and dim, have doubled in efficiency and light output about once every 36 months since the 1960s.
As you probably know, humans have tried growing plants with just about every type of artificial light we've ever created, and LEDs are no exception.
Which has all led to the development of LED grow lights.
At first, no one could successfully grow anything using LEDs. Each individual LED is relatively small and produces only a specific wavelength(color) of light, and we couldn't seem to successfully replicate the proper strength and color of sunlight.
But through trial and error, we've now developed some wickedly effective LED grow lights.
Some people say LEDs work great for growing marijuana, while others claim LED grow lights are junk and can't be used to grow anything.
The truth is that both sides are right.
LED grow lights are relatively new, and they have a pretty poor reputation on the internet for growing cannabis. Some people seem to report good results with LEDs, while others claim they don't work at all.
The truth is that some models work great, while others just don't work for growing cannabis. It's hard to tell which is which unless you just try the different models or use a LED panel that has been tested on real cannabis plants.
One of the biggest problems is there are dishonest companies out there who have no consideration to what's really needed to grow a cannabis plant, and just slap together a bunch of LEDs. Unfortunately some of these poorly made LED grow lights may never grow anything, no matter what you do.
I've discovered that many LED grow light systems just don't work for growing cannabis.
If you grow with poorly designed LED grow lights, your plants may show deficiencies, spots, crispy leaves, and other strange problems. This is why it's important to get a trusted LED brand, even if it costs a bit more than the "bargain" LED grow light you found online from a no-name company.
My search for LEDs started because I live in California, an area where heat can be an issue. I am a small-scale grower who would like to still have a presentable house for guests, so I didn't want to have a hot room or loud fans running all the time.
I wanted to have neat and easy grows in my closet, but I didn't want to have install ducting for ventilation or anything like that, which made HID lights pretty much out of the question for me.
These reason are also what first attracted me to CFLs, which seemed great for a small-scale home grower.
However, even CFLs were producing enough heat to warm up my small grow spaces, especially when I started getting bigger CFL bulbs in an attempt to step up my growing game (not recomended! Stick with smaller size CFLs).
Another thing that attracted me to LEDs had to do with how far away the lights needed to be from the plants. LEDs can be kept relatively far away from plants and don't need to be adjusted often during your grow.
After doing some research, I got a Lighthouse Hydro BlackStar 135 Watt LED grow light in 2012. I got a second one a few months later, I've grown 3 crops in total under just these BlackStar panels, growing two small plants under each UFO LED Grow Light panel.
My yields under the Lighthouse Hydro Blackstar were a bit smaller than what I expected, and throughout the grow my plant leaves appeared a bit beat up (got occasional spots, brown marks, and other signs of light stress, especially the leaves close to the LEDS), but the buds produced with the Lighthouse Hydro Blackstar were always dank, ultra-potent and sticky, even the buds that looked less than stellar had a great quality.
I was pretty satisfied with the results.
Then I had the pleasure of running into other growers who have used specific models of LED grow lights that work FANTASTIC for growing cannabis, even better than the Blackstar (which I was very happy with).
Now, it's been proven that LEDs can be used to grow cannabis plants from the beginning to the end of their life cycle. But are LEDs right for your setup, expectations and budget?
Despite the high initial cost for LEDs, it's easy to see why people want LEDs for their cannabis grow room...
LED grow light systems have some pretty sweet benefits:
Extremely efficient electricity usage, theoretically LEDs are more efficient than any other grow lights
Most models have built-in fans to help disperse heat
LED light systems can be plugged directly into a regular power outlet, and don't need a ballast or special light socket like some other grow lights.
There is some evidence that buds grown under LEDs contain more THC and other cannabinoids (which may be because marijuana produces stronger buds when slightly stressed)
Growing with LED grow lights can positively affect the taste & smell of your buds
Not too long ago, LED grow lights for cannabis always came as a panel with several 1 watt LED bubs. So in the old days, if you got a 90W LED grow light, it used to have 90 1W LED bulbs.
These days, it's much more common to see LED grow lights with an array of 3W or even 5W bulbs.
Something to keep in mind is that the "real" energy output of LEDs is actually only about 2/3 of the stated output. In other words, a "3W" LED really only puts out 2W. That's why you'll sometimes see confusing numbers like a 90W LED Grow light (with 45 X 3W LEDs).
The 3W and 5W LED bulbs are widely considered to have deeper penetration than the old-fashioned 1W bulbs. LED grow lights with 3W chipsets often seem to get the best results, so I recommend getting a 3W model if possible.
The grower from the above journal above uses a Pro-Grow LED grow light, one of the more expensive (and highest-quality) LED grow lights available for medical marijuana.
The Pro-Grow lights are one of the few LED grow light systems
specifically designed and tested for growing marijuana
For those of us who can't afford to spend hundreds of dollars on LED grow lights...
I would like to share a cheaper brand of LED Grow Light that has also been proven to work great for growing marijuana, so you can skip the trial and error.
Lighthouse Hydro BlackStar 135W LED Grow Light
Hydro BlackStar Verdict:
Good choice for the small-scale grower who wants to grow 1-2 plants in a closet
Price: About $180
Pros: Low heat, low electricity use, 1 year warranty, incredible quality of buds produced (seriously the potency is 10/10), can grow two plants with one Hydro Blackstar panel
Cons: Smaller-than-average yields, somewhat airy buds, any leaves closer than 15" to the light can show signs of light stress. This unit comes with a 1 year warranty and you should be prepared to use it - some growers have reported the occasional LED going out; if that happens to your unit, don't hesitate to call and get your lights fixed or replaced!
Here are some pictures of the plants which were grown primarily under the Hydro Blackstar panel. The top three show the plants a month before harvest, and the bottom two photos are from the day of the harvest. The purple pictures show what the buds look like under the LED lights. Click on any of the thumbnails to see a bigger version!
Close-up of the trichromes on one the buds growing under the
135W Blackstar LED Grow Light Panel (3W chipset)
From grower kieflicious: There are 6 plants, but you can only see 5 plants in the pic because the other one is hiding on the right. These buds were grown with HPS for the first 3 weeks, then HPS+ LED, and finished with LED.
There are many different induction grow lights appearing on the market today. These “new” grow lights are supposedly longer-lasting and more efficient than any other grow light.
But what are induction grow lights, and do the claims live up to the hype?
Induction lights are unique because they use induction or electromagnetic fields to transfer power instead of electrical connection or electrodes.
This technology has recently become more popular in recent years, but has actually been around for a long time. The idea of electrodeless lights (induction lighting) came from the famous inventor Nikola Tesla in the late 1800s.
Lights that use this technology are called by many names, depending on the company and how the light gets put together.
Some names for induction lighting include...
- full spectrum plasma lights
- sulphur plasma grow lights
- MPS grow lights
- sulphur lamps
- High Efficiency Plasma lamps
- HEP lighting
- magnetic induction grow lights
- electrodeless lamp
- electrodeless vacuum tube
- fluorescent induction lamps
- and probably lots of other names...
Biggest Benefits of Induction Grow Lights
- No electrodes means a longer life: Induction Grow Lights can theoretically be run for up to 100,000 hours
- Induction lights don’t lose light intensity as fast as MH or HPS grow lights, they stay close to their full initial brightness even after running for tens of thousands of hours.
- Because these lights last for so long, they are popular for stadium lighting, street lights, and other types of lighting where bulbs are difficult or expensive to replace
Yet are the new generation of induction grow lights ready for growing marijuana?
There are two major types of induction grow lights:
- Plasma sulfur induction lights
- Fluorescent induction lights (magnetic induction grow lights)
I first covered these in 2010. Read my full 2010 review on plasma sulphur grow lights, which is still surprisingly relevant today as the technology has remained unchanged.
At that time, a 250W plasma grow light was going for about $1000, and they weren’t even as effective for growing marijuana as a $150 T5 Grow Light that used less electricity.
There have been some improvements to plasma sulfur grow lights, in an attempt to generate light that is more useful for growing plants, but I don’t believe the technology has significantly changed.
Plasma grow lights just are not ready for marijuana growing primetime.
In fact, it seems like plasma induction grow lights have fallen off the growing marijuana radar in the last few years as the initial hype died away.
Yet during that time, magnetic induction grow lights have recently become “the next new thing” in grow light technology...
Magnetic Induction grow lights seem to be the “hot” type of induction grow lights on the market today.
The reports I’ve been receiving seem to indicate that the current magnetic induction grow lights work in situations where fluorescent grow lights work well. This is because a magnetic induction grow light is basically an “electrodeless” fluorescent light.
In other words, magnetic induction grow lights are almost the same thing as a regular fluorescent light (like a T5 or CFLs), only the use induction instead of electrodes to supply energy to the bulb.
This means that these lights will last longer than fluorescent grow lights, with few other major benefits.
Magnetic induction grow lights seem to work very well as a supplement to sunlight or other grow lights, or can be used by themselves.
Should You Go Out and Invest In Magnetic Induction Grow Lights?
Remember, magnetic induction grow lights are basically the same thing as fluorescent lights without electrodes. No matter what sellers try to say otherwise, don’t fall for some of the outrageous marketing claims!
If you’re looking for a magical grow light that doesn’t produce any heat, uses next to no electricity, and produces humongous yields compared to LEDs, MH, or HPS grow lights, then you’re kidding yourself. Magnetic induction grow lights just aren’t what you’re looking for.
If you’re looking for a type of grow light that is low heat, uses a relatively low amount of electricity, has a good form factor for your grow area and you hate replacing your fluorescent bulbs, than magnetic induction grow lights may be the right choice for you.
I hope that helps you as much as it would have helped me when I first looked into grow lights!
If you haven't started growing marijuana yet, today is the day!
If you run into any problems while you're growing marijuana, you don't have to figure everything out alone. Use our handy marijuana problem picture guide to quickly diagnose your plant: http://growweedeasy.com/marijuana-symptoms-pictures
About the Author: Nebula Haze
In response to the need for more tutorials aimed at new growers, Nebula co-founded GrowWeedEasy.com in 2010 with fellow grower Sirius Fourside.
Since then, Nebula has published dozens of growing articles in print and online, stars in online video lessons, and continues to dedicate herself to serving the needs of the medical marijuana growing community.
"My mission is to show other medical marijuana patients how easy is is to grow cannabis out of your closet."
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