Marijuana Grow Lights

… which ones work best and where to buy them?

Always remember: Light == Weight!

Further below: Details for all lamp types and where to get them.

When you grow cannabis, you will put your plants initially under 18 hours of light. For the remaining 6 hours they need total darkness.

This 18/6 hours period is called “vegetative stage”. The plant thinks it is spring. It puts its energy into leaf and stem growth. It will not develop buds.

After 2 – 4 weeks of vegetative growth, you are going to switch the light to 12 hours on / 12 hours off. This will make the plant think that it has become middle/late summer. Time to develop buds!

If you have decided to use different light bulbs for vegetative / flowering stage, now is the time to change them.

If you want to avoid stress for your green friends, don’t switch the light radical from 18 hours on to 12 hours. Go 2 or 3 days with 16 hours / 8 hours and 14/10.

Switching on and off is done by a timer. Not manually. Because otherwise one is likely to forget about it.

(Tip: Click the product images to go to eBay and see pricing)

CFL Grow Lights

Easy to use, for an alright harvest with not too much electricity used.

CFL Quick Tips
  • 2700K = Flowering, 6400K = Growth
  • Not as much light as HPS lamps, but easier to use and not as much heat
  • You can mix 2700K + 6400K and use it through whole grow period
  • Keep them close to your plants for best results
  • You could use 1 x 2700K bulb for whole grow (Cheap Micro Setup)
  • 1 x 150Watt is ok for 2 – 4 plants

150 Watt CFL with Reflector

250 Watt CFL + Reflector

T5 Fluorescent Sets

Pic of mature Sticky Icky MarijuanaCFL Lights are relatively inexpensive. They are easy to use, just plug them into a timer and then the outlet.

They don’t produce too much heat and thus don’t require much ventilation.

And yet, they still yield impressive results.

Available in different colors. 6400K for vegetative phase and 2700K for Flowering.

For a very small setup, just one of these in 2700K with a reflector will do for the whole plant life.

You can get good results by using 1 x 2700K and 1x 6400K at the same time.

Pics of Weed grown under CFL Light:



HPS or MH Lamps

High Pressure Sodium or Metal Halide bulbs deliver fantastic light for Cannabis.

These are slightly more expensive but deliver a lot more light per Watt.

HPS & MH Quick Tips
  • HPS can safely be used for veg and growth phase
  • MH = Growth phase only
  • These produce more light than CFL
  • Produce heat. Ventilation needed
  • 1 x 400W HPS is good for 6 – 8 Plants

HPS are recommended for beginners. You can use them through the whole plant life.

If you want to do a perfect Job, you could get an additional MH bulb for vegetative stadium.

Complete HPS or MH Set

Cost efficient reflector
in 250 Watt, 400 Watt (best option) or 600 Watt

For better quality get DIGITAL system. Listed here.

These lamps come with a Ballast to run them. Do yourself a favor and get one with a digital ballast. They use less electricity, produce more light and the bulb lives longer. Also, they throw less electro-smog. So the digital ballast is very recommended as opposed to the old dirt magnetic ones which are still being sold every now and then.

Get a 250 Watt for a small setup, 400 Watt for average or 600 or 1000 Watt if you want to go above self supply.

I recommend 400 Watt. It produces lots of weed while not overly stretching the electricity bill.

Pics of Marijuana Grown under 400 Watt HPS:

Bud grown with 400W HPS

400 Watt bud

Delicious Buds

Marijuana Grown under HPS lamps looks a bit more “Professional” than the same grown under CFL It is denser and has more volume.

HPS and MH Lights can be bought on eBay here.

LED Marijuana Grow Lights

Led Grow lights can produce great harvests.

LED Quick Tips
  • These can produce great results with little electricity
  • Produce little heat
  • Fake units very commonly sold. Watch for original brand LEDs (e.g. US made CREE)

They are still expensive, but use very little electricity.

Currently, a lot of people sell these with outrageous claims like :”Replaces 400 W HPS” … or so.

That is most often not true. Especially cheap ones on eBay, they don’t really work.

LEDs have big quality diferences. Additionally, brand names are widely faked.

Genuine CREE LEDs seem to be the best. But, they are often faked. It’s important to check the sellers reputation.

Underneath are links to an eBay seller who seems to produce LED grow lights himself. I trust his lights to be genuine.

Also, I have found a remarkable LED Grow light from an engineer in Holland. His name is Hans and he builds, in my opinion, the worlds best LED Grow light.

It cost as much as 4 large HPS lamps. So it is a bit like a Rolls Royce car. It uses quality LEDs and has a switch to change it from vege to flowering phase.

240W LED Grow Light

Small 100W LED UFO

Big 1546 Watt LED

Pretty Powerful system + UVB
Seems like a quality item.

Hans’ LED Light

Hans LED Grow Light
fantastic quality, switchabe for vege and flower.
Bit difficult to buy from Hans but worth it.
More info

Marijuana grown under  Hans 160 Watt LED Light

Marijuana grown under LED Light

Marijuana Grown under 160 Watt LED Grow Light

LED Grow harvest 3.8 ounces

This grow yielded 3.8 ounces (110 gram) for the price of $15 electricity.

2 LED Grow Panels

2 LED grow panels with 80 Watt each. No big fan required because there is not much heat.

LedGrowPanel hanging with fan

LED Panels are modern, silent, cold, beautiful and energy efficient but expensive on initial purchase.

So which Light is best for me?

If you are on a small budget, or have only little space available, or just want to grow a little weed for yourself: Use CFL Lamps. They are easy to use, inexpensive and produce decent results.

If you have a bit of space available, like a pantry or your garage, you could go for HPS Lamps. They produce big, but you’ll need a fan to get rid of the heat and may also need to filter the smell with a carbon filter. Read more about building a grow box, if you like.

If you are settled and have mastered the game of money. Or if you are generally into new and fine things, try Hans LED panels. You’ll have a silent grow box that uses little electricity and yet produces big yields.

Grow Light in more Detail: Light Color

As mentioned earlier, diferrent light bulbs have diferrent colors.

Plants in vegetation mode need more blue light. MH Lights provide that. MH lights even deliver some red light which makes it possible to use them over the whole plant life.

Flowering plants need more red light, as supplied by HPS lights.

The CFL Lamps are available in red, blue and mixed colors.

Light Color (also called light temperature) is described in Kelvin. 2700 K is a very red spectrum for flowering. 6400 K is a cool blue/green light, as needed for growth. There is also 14.000 K available which has even more blue.

Light Color Temperature Table

Used for Kelvin Color Name Color
Growing around 6400 Daylight, Cool blueish
Flowering around 2700 Warm yellowish – redish

Types of Lamps and their color.

There are High Pressure Lamps, Compact Flouro Lamps and LED Lights available. They all have their strength and weaknesses.

High Pressure Lamps

These are the (still) most commonly used Lamps.

Their brightness and good light color bring great results as Marijuana Grow Lights.

However, they also use a lot of Energy (200 – 600 Watt) and produce a lot of heat. Strong ventilation systems are needed. High Pressure bulbs also need a balast to start them up.

High Pressure Sodium Lights (HPS).

Marijuana Grow Lights

High Pressure Sodium Lights emit an orange/red light. Cannabis needs this during the flowering stage.

These Bulbs have a lifespan of ca. 24.000 hours.

High Power Grow lights

Metal Halide Lights (MH).

Marijuana Grow Lights

They send out light in the blue spectrum, which is used in the vegetative (growth) stage of plants.

These bulbs also emit some red. Therefore they can be used for flowering, too. They will yield a good harvest. These bulbs are the best option when you decide to grow under high pressure bulbs.

One disadvantage of MH Lights is their relatively short lifespan of only 10.000 hours.

Compact Fluorescent Lamps (CFL)

Marijuana Grow Lights

A very inexpensive but good option is the use of Compact Fluorescent Lamps (CFL). As shown on the left.

The bulbs are fairly cheap. They do not need a ballast. They run relatively cold

One Lamp with at least 100 Watt will be enough for 1-2 plants. Better use 2 CFLs.

They are available in diferrent colors for vegetative (6400K) and flowering stage (2700K). I had success even with using only one flowering bulb for the whole plant life.

Compact Fluorescent Grow Lights

ctor (except with LED lights) for more efficiency with your Marijuana Grow Lights. Very recommended.

Learn how to build your own Grow Box

  • Juan

    Hello, I am relatively new to grow. I just finished germinating 2 good seed and put the in dirt. They have already sprouted out, about a half inch high. I have them in a small planter outside. When they are ready, I am going to bring them inside in my closet. What should I be doing? As far as lights, nutrients, sunlight, ect… Thanks in advance

  • George

    this is my first time grow. up until now ive just been using 36watt fluorescent tubes with a 24hr light cycle and they are going surprisingly well , they did get a fungi but ii quickly acted fast on that with some eco-fungicide. i just did a repot and now im moving them to a bigger space 1m x 0.5m x 1.5m. i was thinking of going for a 400 watt hps for 4-6 plants but im still unsure. i was also wondering will they NEED any nutrients through the flowering stage because i dont like the idea of pumping them with chemicals, so ive just been watering and spraying them with diluted seasol and they love that.

    • Jack Tambo


      thanks for the pics.

      yes, they look healthy good work.

      They need nutrients, yes. This is a very hungry plant. Spraying the leaves is good, but not enough.

      Especially when you switch to 400W HPS they will get hungry.

      You could try organic fertiliser like this:

      • George

        thank you!

  • gwnys

    I assume since the lights discussed here are specific and pricey that the LED strips available that are controlled, as in set led color and intensity, that those would be worthless for growing? Here is the item offered; “OSRAM LED Strip LIGHTIFY Flex Strip RGBW / Flexible modules / light color and color temperature adjustable – Warm White to Daylight (2,700K…6,500K) / 3 – 2ft Strips with power supply.”
    So since no one seems to use these am I correct that they would be useless for growing in a closet.
    Thanks for the advice, and please don’t ridicule this newb’ for asking.

    • Jack Tambo


      well, they might even work.

      But you’d need a lot of them. And then you’d need to control them. And you need to make sure you buy genuine Osram, because those are often faked and then they have less light intensity.

      So its just easier to buy a readymade LED grow light. I thing is the best one.

      Cheers, Jack

  • Lookham03

    Hi Jack, i’m new to this green fingered game. I’ve got a 1m x 1m x 2m grow tent. Its gonna be in my outhouse/garage. I live in the uk. I’ve got a 300w cfl lamp. canna soil, and all the nutrients to set me up. I’m just worried about a) the light being good enough for 4-5 plants. 2) do they need heat?
    Your posts are very valuable! Thanks for all the info i have read so far!

    • Lookham03

      Purchased another 300w duel spectrum CFL. Supposedly these bulbs put out 21’000 lumes so i figured having 2 of them should be the equivalent of a single 400w hps. Would that be ok in a 1m x 1m x 2m mylar reflective buddah tent? For 4-6 plants? Any advice/help would be appreciated guys! Thanks

      • Jack Tambo


        I would think that 2 x 300W CFL is good for 4-6 plants.

        Just making sure: You are using those huge CFL bulbs that actually use 300 Watt, correct? As opposed to some CFL that claim to be the equivalent of a 300 Watt bulb.

        Good thing is you can hang them pretty close over your plants because they don’t run too hot.

        • Lookham03

          Hi Jack!
          Yes its the huge bulbs, 300w actual. I have 2 of them with the dual spectrum lighting. I have the carbon filter and the ventilation system in place. I was just worried about the cold nights while the lights are off, will i need to put a little heater in there to keep the temp up? Is there a certain temp it cant fall beneath?
          Thanks for the advice.

    • Jack Tambo

      they won’t need heat, unless you have the tent outside in a shed in winter? The lamp will usually produce enough heat

      Your light is a bit on the small side. It would work ok for 2-3 plants.

      Have you considered using 1 x 250W HPS instead? You’d get more light for the electricity used.

      You tent is a good size, you will need some ventilation as well.

      Happy growing!

  • Cake

    Hey guys.

    As alot of people here are, I’m new to growing and would like some advice.
    I have a space of 7ft x 7ft, and am beginning with 6 plants. I plan to use two 150watt CFL lights as my bugdet is low. Will this lighting be enough for growth of both stages if I have 2700K and 6400K lamps together? Also my room is an old wooden shed, and I’m looking for any cost effective method to have decent light reflection.

    I am open to and appreciate any suggestions or recommendations for a ‘budding’ florist? Thank you!

    • Jack Tambo


      2 x 150 Watt is at the low end for 6 plants. For 3 it would be ok.

      With 2 x 150 W, you are using 300W. Have you considered using 1 x 250W HPS instead? That would work better for 6 plants.