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Which Grow Light? | Marijuana Grow Light Guide

by Nebula Haze

Generally speaking, when growing marijuana, More Light = More Buds

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.

This info will come in handy when trying to choose the best marijuana grow light for you.

How to Compare Marijuana Grow Lights

Skip right to the cannabis grow light section you want to learn about...

I Want Cheap "Starter" Marijuana Grow Lights
Warning! No matter which grow light you choose, make sure you get a surge protector

HIDs - High Intensity Discharge Grow LightsHigh Pressure Sodium Grow Lights (HPS) are the golden standard for growing marijuanaMetal Halide Grow Lights (MH) give off a wonderful light spectrum for marijuana's vegetative stage

CFLs - Compact Fluorescent Lights

Fluorescent Grow Lights like the T5 can be a low heat, low electricity option for growing marijuanaCFLs can make great grow lights for small, stealthy growsT5 Grow Lights & Other Fluorescent Lighting

LEDs - Light Emitting Diodes

Induction Lighting: includes Magnetic Induction Grow Lights & Plasma Grow LightsLED grow lights are low heat, low electricity marijuana grow lights

Induction Lighting

Introduction to Indoor Grow Lights for Marijuana

Incandescent light bulbs are NOT suitable for growing marijuanaAre 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, and they need to get a lot of light in order to make enough energy to grow big, then produce buds (marijuana flowers).

Generally, you will need special types of lighting to grow marijuana, though some regular house lights can work too, if you know what to do.

Please note: Incandescent light bulbs are NOT suitable for growing marijuana!

When growing marijuana outdoors, sunlight is generally all the light your plants needOf 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.

Yet as an indoor grower, there's a few things you should know about lights and growing marijuana. You see, marijuana is a short-day plant, which means that marijuana plants don't start making buds until their "days" become short enough.

The length of time that your cannabis gets light and darkness each day will determine when it starts flowering (making buds). Most marijuana plants need long (12+ hours) nights to start flowering.

The major factor that determines when most marijuana plants start flowering is the length of the photoperiod, or how long the plant receives light and total darkness each day.

Outdoors, the sun is in charge of when your plants start budding. When the days start getting shorter as winter approaches, your marijuana plants will naturally start flowering.

Use an automatic timer to turn your marijuana grow lights on and offIndoors, you are in control of when your plant starts budding. You do this by adjusting the plant's daily light schedule, usually by hooking up your grow lighs to an automatic timer.

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 marijuana seeds. Where do I buy seeds?

Auto-flowering plants tend to be less potent than non-auto-flowering plants, but not always.

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/yellow spectrum simulates sunlight from the Fall/Winter. 

The color spectrum of your grow light will have a much smaller effect on your plants than the photoperiod, and I wouldn't worry too much about it if you're a beginner. As long as you buy a grow light that is meant for growing weed (like all the ones listed on this page), then your color spectrum will be close enough to get great results. After you have a few successful grows under your belt, you can start to worry about maximizing your light's color spectrum.

(Where can I safely buy marijuana seeds online?)

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 buds can often be even more tasty and potent than similar marijuana buds grown outside.

The most common types of lights used indoor with marijuana is High Intensity Discharge (HID) lights such as High Pressure Sodium (HPS) and Metal Halide (MH) lights.

These grow lights are powerful and proven to provide great yields, though they use quite a bit of energy and produce a lot of heat for a small grow space.

WIth HID lights, you will get the best results of any grow light, but will generally also have to install some sort of exhaust system to properly deal with the heat.

You can also grow marijuana plants using Compact Florescent Lights (CFLs) and LED grow lights which both use less power and produce less heat than HID lights.

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 marijuana grow lights by grow style..

Starter Grow Lights

CFLs can make great grow lights for small, stealthy growsFluorescent Grow Lights like the T5 can be a low heat, low electricity option for growing marijuana
CFLs or flourescent lighting

  • Grow A Few Short Plants
  • It's Hard to Scale Up to More/Bigger Plants With These Types of Lights
  • Great If You Just Want to "Dip Your Feet" and Try Growing Out
  • Cheap to Set Up and Maintain
  • Stealthy - Low Heat, Low Electricity
  • Compatible With A Very Small Grow Area, Even Inside A Computer Case!
  • If You Get Serious About Growing, You'll Probably Have to Upgrade to Another Type of Grow Light (You'll Still Be Able to Use These Lights For Young Plants, Cloning, and Supplemental Lighting)
  • Perfect For A Beginner With a Small Budget

For a cheap, small grow of 1-3 plants, for someone who doesn't have a lot of money to spend, with a small grow area, where, or who just wants to give growing a try, your best choice is either CFLs (compact flourescent bulbs) or other flourescent lighting (such as the T5 grow light)

Feel free to check out my tutorial that will show you how to start growing marijana with CFLs for less than $300.

Deluxe Grow Lights

Metal Halide Grow Lights (MH) give off a wonderful light spectrum for marijuana's vegetative stage High Pressure Sodium Grow Lights (HPS) are the golden standard for growing marijuana
MH / HPS Combo (HID Grow Lights)

  • Grow Unlimited Plants Indoors
  • Very Easy to Maintain Once Set U
  • These bulbs cannot be plugged into a regular ligh socket; they need a special hood and balast (usually sold together) 
  • More Heat Produced & More Electricity Used Than Other Grow Lights
  • Need A Big Space or An Exhuast System to Deal With Heat 
  • Can Be Expensive to Set Up The Grow Area
  • Most Tried-And-Tested Grow Lights (Growers Have Spent Decades Perfecting The Process of Growing Marijuana Indoors With HID Grow Lights)
  • Consistent Big Yields Of Potent Medical-Grade Marijuana
  • Because People Have Been Growing With These Lights For Years, There Are Lots of Growing Resources, Making This One Of The Most Problem-Free Ways To Grow 
  • Recommended for Serious Growers Only Due To Setup & Electricity Costs

If you have a bit more money to get started with, 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.

HPS lights can be used for the whole grow cycle and work really well. 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

LED grow lights are low heat, low electricity marijuana grow lights
LED Grow Lights

  • Stealthy - Low Heat, Low Electricity
  • Easy & Cheap To Maintain Once Everything Is Set Up 
  • High Inital Cost, LED Grow Lights Currently Cost More Than Most Other Grow Lights
  • LED Grow Lights Are The Wave of the Future - LED Grow Lights Are More Efficient Than Other Grow Lights, But...
  • New Technology - Some LED Grow Lights Work Great, Others Barely Work At All... It's Important You Choose the Right Model For Growing Marijuana
  • Can Be Problematic to Get Everything Set Up Properly Since The Technology Is Constantly Improving/Changing (Don't Worry, Will Walk You Through The Process of Picking the Right LED Grow Light)
  • LED Grow Lights Continue To Get Better & Better -  Marijuana Yields Are Going Up While Prices Keep Coming Down

For the advanced grower who wants to use the most cutting edge technology, or for those who desire low heat and low electricity above all else, than LED grow lights are the best choice for you. 

Supplemental Grow Lights
(easily add more light to your grow)


CFLs can make great grow lights for small, stealthy growsFluorescent Grow Lights like the T5 can be a low heat, low electricity option for growing marijuanaInduction Lighting: includes Magnetic Induction Grow Lights & Plasma Grow Lights
CFLsflourescent lighting, or induction lights


  • Low Heat Produced
  • Low Electricity Used
  • Simple Maintainance
  • Perfect for filling in shadowy parts of the plant with more light, or can be used as side lighting

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, CFLsflourescent 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.

And Now For The Complete Marijuana Grow Light Breakdown...



Metal Halide (MH) & High Pressure Sodium (HPS) Lights

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.

How to Set Up Metal Halide (MH) or High Pressure Sodium (HPS) Grow Lights
View Full Step-By-Step Picture Tutorial on How to Set Up
Metal Halide(MH) and High Pressure Sodium (HPS) Grow Lights

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 use more electricity and produce more heat than pretty much any other type of grow lights. 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) Grow Lights for Growing Marijuana

Metal Halide (MH) lights produce light that has more blues and whites in it than the sunlight's natural light spectrum, which makes it most suitable for use during the vegetative stage of your marijuana plants. 


Metal Halide (MH) for the Vegetative Stage

Metal Halide - MH for the vegetative stage of marijuana growth

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.

High Pressure Sodium (HPS) grow lights for growing marijuana

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.

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.

High Pressure Sodium (HPS) for the Flowering Stage

HPS lights are perfect for flowering marijuana plantsMost 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 initially stretch upwards in a last spurt of growth, and from then on to focus all their energy into growing buds.

Choosing your MH or HPS Grow Lights

If it's your first time growing with an MH or HPS grow light, I recommend buying your bulb(s), ballast, and hood (reflector) together as a set, like the one pictured to the left.

This just makes things easy and lets you focus on growing marijuana instead of worrying about matching 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. More on that in a second.

For HID grow lights, 150-250 watt bulbs are suitable for 1-3 plants and will cover an area measuring 3 feet square (3x3).

I generally recommend against getting an HID bulb that is less than 400W, as they're just not efficient and you'll often get better results in that small a space with CFLs, LEDs, or fluorescent lighting such as a T5.

Many growers choose to get a 400 and 600 watt bulb/ballast which is suitable for 4-12 plants.

You can get 1000 watt (or more) bulbs, and this is especially common with high-yield and commercial operations, which can use light movers, lots of CO2, and other relatively expensive tactics to get more yield out of a certain small indoor area.

For a small-time grower, it is often more practical to get 400W or 600W grow lights, as these produce much less heat than 1000W bulbs. If you need multiples of 400W and 600W MH/HPS grow lights, they can often be easier to space out evenly in a small grow space than bigger wattage bulbs. 

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 they use.

Still not sure which HID grow light?

Walk me through the process of picking out the right MH or HPS Grow Light for my situation.

If you must choose just one type of HID light, 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..

As far as maintenance and setup, Metal Halide and High Pressure Sodium bulbs are pretty much the same.

How to set up MH or HPS Grow Lights

Show me how to set up my MH/HPS grow lights step-by-step

All HID lights (Metal Halide or HPS) require that you have a...

  • Ballast (which usually plugs into a standard power socket)
  • Bulb
  • Hood (reflector) 
  • Optional: Exhaust (usually a fan plus ducting to vent out heat)

These lights need a ballast to control the flow of electricity to the lamp, which means they can't just be screwed into any sort of regular light socket.

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.

Because HID lights produce so much heat when in use, almost all growers will need to get some sort of exhaust or ventilation system.

An air-cooled hood for a 600W HPS lightThis is also why most people prefer an air-cooled hood (pictured to the right).

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).

It's easiest to buy the whole HID system together as one unit instead of buying all the pieces separately. There's nothing more frustrating than trying to fit parts together that just don't quite work!

By the whole system I mean the bulb, ballast and hood (reflector).

You can purchase a system that suits all your needs, and 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. 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 anyway.

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.

Help me find the right MH or HPS grow light for my budget


Compact Florescent Lights (CFLs)

CFLs make great marijuana grow lightsThe term "CFL" is short for "Compact Florescent Light." 

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.

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.

Growing marijuana with CFL grow lights
Read tutorial on how to grow weed with CFLs

Some of the bigger CFL bulbs (especially the ones over 80W) start to produce a lot of heat. If you're going to grow a lot of plants, or really big plants, you may want to upgrade to an MH/HPS combo as CFLs are really only suitable for a small grow of 1-3 marijuana plants.

"Soft White" CFL grow lights are perfect for marijuana flowering stageBy the time your plants have started flowering, you may 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 plant.

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.

There are lots of way to get creative when growing with CFLs. This item splits 1 CFL light socket into 4.When looking for clamp light sockets, avoid anything that's made of plastic (it's cheap and will break if it doesn't melt) and try to find something with at least a 9 foot long cord.

You'd 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.

Read step-by-step tutorial on how to grow marijuana with CFLs

A heavy-duty clamp light socket with reflectorTwo Compact Florescents put into one plug using a twin socket adapter and a light socket extender

An incredble CFL grow light setup by grower iskraiskra
Example of a great CFL setup for growing cannabis plants by grower iskraiskra
(click pic for closeup)

T5 Grow Lights & Other Fluorescent Lighting

T5 Fluorescent Grow Light System for growing cannabisA few years ago, the only real use for fluorescent tube lighting was as a supplement to your cannabis plants, or to be used for young seedlings and clones only.

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, or to supplement you fluorescent tubes with additional light during the flowering stage.

For example, after your plants have entered the flowering stage, you could supplement their light with a few CFL(compact fluorescent light) bulbs wherever you notice any "shadowy" areas.

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.

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.

T5 Fluorescent Growth Lights make happy young marijuana plantsThe great thing about fluorescent grow lights is that they don't get hot at all, and they can 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 more energy efficient than many other types of lights, and therefore 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 because they are the most advanced, give off the most amount of light per watt used, and are specifically designed to be able to support taller plants up to 24 inches.

For optimal results, choose fluorescent light bulbs that are labeled either as "Cool White" or "Cool" colored for vegetative growth (Cool White is also labeled as "6500k" colored.

Choose bulbs that are "Warm White" or "Soft White" colored (usually labeled as "2500K"  or "3000K") for flowering growth.

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!

Many cannabis growers have successfully used T5s to grow buds

LED Grow Lights

You may or may not know about the LED grow light craze among marijuana growers.

LED grow lights use less energy and generate much less heat than standard HID grow lights, so there's good reason for all the attention.

Today, I'll be answering the following questions:

  1. Why is there so much controversy about whether LED grow lights even work?
  2. Which companies, if any, have the best LED grow lights (specifically for growing marijuana)?

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.

Now, I'm talking about grow lights made of light emitting diodes, 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.

See 3 cannabis plants grow from seed to harvest under a 250W LED grow light

And LED grow light systems have some pretty sweet benefits:

  • Extremely efficient electricity usage, theoretically LEDs are more efficient than any other grow lights

  • LED light systems run cool and many models do not need anything extra to control heat

  • Most LED light systems can be plugged directly into a regular power outlet, and don't need a ballast or special light socket like many 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 by closely mimicking the light of the sun

Now, it's been proven that LEDs can be used to grow marijuana plants from the beginning to the end of their life cycle.

I know this is true because I have personally have grown marijuana plants from seed to harvest with a Lighthouse Hydro BlackStar 135 Watt LED grow light system.

My search for LEDs started because I live in an area where heat can be an issue. I am also a small scale grower who would like to still have a presentable house for guests.

Where I was living at the time, 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.

Based on the experiences of some of my fellow growers, I discovered many LED grow light systems just don't work for growing marijuana.

After doing some research, I got my 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 normal 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-poten and sticky.

The incredible quality of the buds kept me trying to find ways to up the total yields.

Plus I was saving money on my electricity bill (electricity use with the  Lighthouse Hydro Blackstar LED Grow Light was minimal), and there was no heat to speak of, which really simplified the heat situation in my tiny, tiny closet.

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.

So LED grow lights can work, but at the same time, it is true that some models work much better than others. And there really are dishonest companies out there who probably just slapped together a bunch of LEDs, which no consideration to what's really needed to grow a plant, and these LED grow lights will never grow anything, no matter what you do.

Not too long ago...

LED grow lights used to always come 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 and 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. Therefore it's recommended that you get an LED grow light with 3W bulbs or bigger.

Fat bud grown under a 90W LED grow lightWhile each individual bulb doesn't produce a whole lot of light, LED bulbs can be manufactured to produce light that is in the spectrum that the plant needs to grow.

With other grow lights, while they may be powerful, a lot of the light produced is in a spectrum that the plant just can't use to grow.

Because the newer LED grow lights are being made to produce only the needed light spectrum without all that extra, they may be able to get better results using the same or even less electricity.

The main benefits of LED lights is they may be more efficient than other grow lights, (meaning they may use less energy and produce less heat for the same amount of electricity), and they can be plugged directly in the wall without a ballast.

However, LED grow lights are relatively new, and they have a pretty poor reputation on the internet for growing marijuana. 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 marijuana. It's hard to tell which is which unless you just try the different models.

As I mentioned before, I live in an area where heat can be an issue and I am also a small scale grower who would like to still have a presentable house for guests.

When I first started growing, 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.

I wanted to have neat and easy grows in my closet.

That's what first attracted me to CFLs, which are great for the small-scale home grower.

However, even CFLs were sometimes producing enough heat to warm up my small grow spaces, especially when I started getting bigger 105W CFL bulbs in an attempt to step up my growing game (not recomended!).

Closeup of marijuana under an LED grow lightStill not wanting to have to invest in an exhaust system, I became interested in LED grow lights because they seemed to be even better than CFLs as far as heat output and electricity use. 

Another thing that attracted me to LEDs had to do with how far away the lights needed to be from the plants.

One of the nuisances with CFLs is that you need to keep the bulbs only 2-4 inches away from the plant at all times for optimal growth. If the bulb is further away, your plants don't get much usable light. If the lights are closer than 2 inches, they will literally burn the leaves of the plants because of the heat of the bulb.

Having to keep your lights in the 2-4 inch distance range can be inconvenient if your plants are growing rapidly or if you need to be away from your plants for a few days.

Because LEDs barely produce any heat, it doesn't matter as much if the plant grows into the lights because the LEDs don't produce enough heat to burn the leaves.

Because of all the benefits, I knew that I needed to at least try an LED grow light panel.

See an entire grow (seed to harvest) with LED grow lights

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.

Pro Grow X5 LED Grow Light
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
(3W Chipset)

Learn more about the Hydro Blackstar

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!

This is the bud off of a White Rhino plant that has been growing under the eLoofa LED panel. The buds appear purple/black when they're under the LED light. This bud off of a White Rhino plant was grown primarily under the eLoofa LED panel Extreme close up of White Rhino bud grown under the eLoofa LED grow panel

A White Rhino Cannabis plant grown under the eLoofa LED panel These just harvested White Rhino buds were grown primarily under an eLoofa LED light panel

Close-up of the trichomes on one of the White Rhino buds grown under a 90w LED grow panel
Close-up of the trichromes on one the buds growing under the
135W Blackstar LED Grow Light Panel (3W chipset)

Another Lighthouse Hydro BlackStar Pic
(with bigger versions of the lights: 2 x 240w and 1 x 500w)

2 x 240w and 1 x 500w, all Blackstar LEDs. There are 6 plants, but you can only see 5 plants, the other one is hiding on the right. Keep in mind, these buds were grown with HPS for the first 3 weeks, then HPS+ LED, and finished with LED

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.


See a complete medical marijuana grow under LED grow lights



Induction Grow Lights
(Magnetic Induction or Plasma Grow Lights)

Read full article on induction grow lights for marijuana

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 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)

Sulphur Plasma Induction Grow Light

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

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.

Learn more about induction lighting for growing marijuana!



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!

Our one-of-a-kind 2-page Stealth Growers Cheat Sheet will teach you everything you need to know to discretely start growing a few pounds of marijuana a year, out of a spare closet.

Click here to learn how to grow weed and download your cheat sheet

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:

About the Author: Nebula Haze

Nebula Haze - Grow Weed

In response to the need for more tutorials aimed at new growers, Nebula co-founded in 2008 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 and fun it can be to grow pounds of killer weed out of your closet."

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