Marijuana Grow Lights

Light = Weight

About Marijuana Grow Lights

Marijuana Grow Lights are one of the most important ingredients to achieve good grow results. The more light, the more weight your harvest will have.

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

Grow Lights

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.

The switching of the lights is done by a timer. Not manually. Because otherwise one is likely to forget about it.

CFL Grow Lights

Pic of mature Sticky Icky MarijuanaThese are recommended for beginner growers on a small budget.

They 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.

Available in 150 Watt or 250 Watt.

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

This weed was grown under CFL Light:


Grown under 210 Watt CFL Light


Weed Grown under 210 Watt CFL Light


Grown under 210 Watt CFL

CFL Grow lights can be bought on eBay here.

HPS or MH Lamps

HPS Light with ReflectorHigh Pressure Sodium or Metal Halide bulbs deliver fantastic light for Cannabis.

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

They run quite hot and you will most likely need ventilation when using them.

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.

These lamps need a Ballast to run. These days, digital ballasts are common. 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 Watt if you have lots of space and large cahunas.

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

This Marijuana was Grown under 400 Watt HPS:

Marijuana under 400W HPS Light

Marijuana Growing under 400W High Pressure Sodium Light

Bud grown with 400W HPS

Marijuana Bud under 400W High Pressure Sodium Lamps

400 Watt bud

Cloese-up Photo of Bud grown under 400W HPS

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 Lights

P1010021  Led Grow lights can be pretty good.

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.

I have found one remarkable LED Grow light from an engineer in Holland. His name is Hans and he builds, in my pinion, 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.

Have a look if you like.

This Marijuana was grown under 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.

The Hans LED Panel can be bought here.

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.

Do not use HPS during the vegetative stages of your plants growth.

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

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