Feeding the best “light” to your cannabis plant: choosing the right grow lamps

10 min read

The light cycle of marijuana is as essential as the light cycle of any other plant.

That’s when it uses the sunlight as a source of energy for photosynthesizing and releasing oxygen.

But not all plants bring as big a dilemma as marijuana does.

The fact that cannabis needs light and encircles legal controversies— you are likely to get caught between the thoughts whether to grow it or not.

Growing it in broad sunny outdoors can land you up in jail, and cultivating it in secret may snatch the vital nutrients and light from your cute little plants.

Either way— growing cannabis can be an arduous task for you— and that can be depressing if you love snorting.

But it’s not the end of the world.

If the legal laws of the land allow you to grow marijuana, you can build your marijuana greenhouse and regulate the lighting at day and night time.

And if it doesn’t, you can still settle with indoor marijuana cultivation by installing a few devices and creating a replica of the outer environment.

Moreover, if indoor cultivation takes away the natural environment for the sustenance of plants, they give your plants the added advantage over wild weather such as torrential rain, snow, and windy storms.

Having said the pros and cons of indoor growing, the process of indoor cultivation has bettered with time as renowned growers have applied experimenting techniques to get the best output with optimal resources.

And these growing grandmasters have worked mostly on evolving lights by which they can voluntarily control the growth cycle.

If you have finally decided to go with indoor or greenhouse growing space, we are assuming that you have created actionable roadmaps relating to light, air, and water management.

So, without further delay— let’s find out the “good meal” serving your cannabis plants in the form of best lighting bulbs.

Best Lighting For Growing Weed

There are a variety of grow lights in the market, and each bears its pros and cons.

Furthermore, not all can be applied to every condition.

You may have to change the bulbs under different circumstances depending on the stages of the growth cycle.

Different sizes have different operatives which are mainly responsible for accelerating or decelerating the speed of growth and the health of the plant.

Here is the list of grow lamps which you should use to grow cannabis.

  1. LED grow lights
  2. Fluorescent grow lights (T5 and CFL)
  3. Metal Halide grow lights
  4. High-Pressure Sodium grow lights

Let’s cover all these bulbs in detail.


The Key Highlights Of Grow Lights.

#1 LED grow light

  • LED grow light has brought radical changes in the indoor and greenhouse marijuana cultivation.
  • It is extremely easy to install and go well with small indoor spaces.
  • You can simply plug it, and it is ready for use— that’s it.
  • It is one of the easiest set-ups which produces quality yield at low cost.

How to install LED grow lights?

  • Once you have plugged it into the electric board, you should make sure that it sits above your plant’s head.
  • Ensure that plants and bulbs have enough distance between each other so that you could prevent heat and light burn.
  • See to it that you are getting green and white light for full spectrum growth as red and blue lights are incompetent to give desirable yield.
  • Although it emits moderate heat amount, you should install the exhaust, cooling fans, and proper ventilation for organizing the airflow and regulating the right temperature through the entire growing course.

When should you go for LED grow lights?

  • LEDs are potent for as small as 1 to 1.5 ounces of cannabis per month. So, if that’s your goal— heads ahead!
  • If you are trying to become a professional grower and wish to have a massive yield, LED grow lights shouldn’t make it to your list because it has lower yield per watt in comparison to other lights available in the market.

#2 Fluorescent grow lights (CFL and T5)

  • Fluorescent grow light goes well with the infant stages of your plants.
  • It consumes low-energy and is very pocket-friendly for most of the growers— that’s what makes it popular among non-professional weed-growers too.
  • It’s easily available in the market and hardware stores.
  • It comes in different sizes; however, CFL bulbs which are super compact with easy-availability can play brilliant fit for your lovely garden.
  • The long tube-like fluorescent light, i.e., T5 grow light is also one of the go-to solutions for growing your plants.

How to install fluorescent lights?

  • Unlike LED plants, you can place these lights close to the plants— it will fasten the growth cycle without burning them.
  • Use purple-white spectrum light.
  • Akin to LEDs, these lights produce moderate heat. However, you should still not compromise with airflow and ventilation.

When should you go for Fluorescent lights?

  • Fluorescent lights go best with your hobbies. If you like gardening at home, or want to boast indoor produce among your weed-circle— CFL and T5 will help you achieve your social objective.
  • Go for it when you are not bothered with smaller yields.
  • CFL is ideally suitable for narrow or small areas. That’s the reason why it’s prominent among beginner growers.
  • If you are longing to become a professional grower— pick T5 among the two.
  • If you have been planning to clone and feed light to the young plants— these lamps can just fulfil your need.
  • If you have been seeking an ideal light for seedling plants— the white-purple spectrum can keep up with your requirement.



#3 Metal Halide grow lights

  • Metal Halide is one of the most efficient grows lights in the growing industry.
  • It’s an electrical lamp with high-intensity discharge (HID) gas.
  • It has a high yield per watt of electricity, i.e., the amount of light it produces is worth the amount of power it consumes.
  • In fact, it’s the most efficient light after High-Pressure Sodium discharge lamps as it has deeper light penetration and covers a large area.

How to install Metal Halide?

  • The lamp has to be attached with an external ballast as it already has the integrated fixture for it.
  • Don’t place it close to the plant as it may cause burn.
  • Keep adjusting your HID, depending on the level of the growth cycle.
  • One or two fixtures are enough. You don’t have to install multiple CFLs and adjust them over 2” plants.
  • Ventilation is a must as it has high heat output.

When should you go for Metal Halide?

  • If you want to cover a large area just with one or two bulbs, Metal Halide will remain consistent with your desires.
  • Metal Halide (HID) is intuitive to use. If you have used it— you can easily understand the complex set-ups like LEDs and CFLs which need regular monitoring and adjustments.
  • It’s a precise fit at the vegetative phase as it generates a bluish spectrum. So, for a productive vegetative stage, Metal Halide will do worlds of good to your final cannabis output.

#4 High-Pressure Sodium Grow Lights

  • The daddy of all the lights— high-pressure Sodium (HPS) grow light— is also a high-intensity discharge lamp which has a tremendous heat output.
  • It’s an expensive arrangement for a wonderful plant output.
  • Despite being similar to Metal Halide, it has more efficiency than any growing bulb available in the market.
  • HPS has the deepest light penetration, which yields quality raw.
  • It has a humongous luminous effect with regards to the electricity it eats.

How to install High-Pressure Sodium Grow Lights?

  • The height of the lamp over the plant continues to be the most important aspect to watch out while cultivating cannabis.
  • Pretty much like Metal Halide— the HPS has an integrated fixture. Make sure that you attach it correctly with the external ballast.
  • HPS lights are best suited with reflector hoods.
  • Set-up an exhaust system and ventilation which manage the inflow and the outflow of heat and light.

When should you go for High-Pressure Sodium Grow Lights?

  • If you don’t want to change up your set-up at different stages of cultivation— you can use HPS which radiates yellowish and red light spectrum.
  • Your plants need yellow and red lights for flowering and purple for vegetative stages. For cost-cutting, you can simply swap Metal Halide bulbs with HPS and voila! Your plant is sitting comfortably on the budding stage. (Considering the ballast size is same for both the lamps)
  • You’d need HPS to grow light if you want to go professional with cannabis cultivation.
  • The light makes sense in all the scenarios— whether grow tents or large grow rooms homes or even greenhouses. So, get it in your growing space without having to adjust tens and hundreds of CFLs and LEDs.

Now that we have covered all the standard bulbs in the industry, you must be intrigued when to use which lamp.

Well, some growers go with the same lighting packages irrespective of the growth stage of the plant.

But smart and professional growers have a deeper understanding of the interaction between lights and plants.

Think of plants as humans— they need different nutrients and food from infant to developing, and adolescent to the advanced stage.

Apply the same rule to your garden, and live by the extremely popular saying— “feed your plants as you’d do to yourself.”

For your curiosity, we have brought a series of pro tips which can make an expert grower out of you.


Here’s the quick scan for understanding the interaction between plants and lights.

  • A standard 60-watt incandescent bulb (also the regular light bulb) won’t work for your garden or field.
  • If you are in the cloning or seedling stage, T5 fluorescent grow light is your answer to them.
  • As soon as you enter the vegetative stage, get rid of T5 lights and install HIDs. Since Metal Halide Lamps are the “lighting haven” during the vegetative period, make sure that you install them instead of LEDs.
  • You can maintain the ratio of 2 Metal Halide lights to 1 HPS light if you want to maximize yields during the vegetative session.
  • Your plants need red light during the budding/flowering phase. Say goodbye to Metal Halide lights and replace them with HPS bulbs which promote easy budding.
  • Pre-install exhaust fans for HPS and Metal Halide bulbs as they can shoot “scorching heat waves” to your plants.
  • Use exhaust fans for LEDs and CFLs as well— because you want to have control over temperature whenever the conditions don’t meet the needs of the plants.
  • HPS and Metal Halide are 2 to 4 times luminously stronger than LEDs and CFLs. Make sure that you have enough space to install these over-bright bulbs so that you don’t burn off your plants.
  • Plants get habituated to the light which you feed them from the infant stage. While you are switching from one light cycle to the other— ensure that you do it gently and not instantaneously. Take at least 36 to 48 hours to convert from 18/6 to 16/8 to 14/10 to 12/12 hours.

The final light on the subject…

Cultivating cannabis is as good as nourishing a child— you have to take care of its nutrients and food (light) at each stage of its life cycle.

For “not so professional” growers— you might choose cheap lights to cut down the cultivation cost; however, the quality of your cannabis solely lies in your hands.

As grow lights work as the bloodline of the plant’s growth— you can’t afford to overview it.

The saying literally turns into “you reap what you sow” if you compromise with the light bulb set-up.

If you still want to grow cannabis out of “passion” but not want to make it a “profession,” and if you are budget-constrained— use fluorescents and LED lights in the initial and vegetative phase and drop them out in the natural sunlight for the ultimate flowering

LEAVE A REPLY

Please enter your comment!
Please enter your name here