Best Grow Lights for Indoor Cannabis Growing

Best Grow Lights for Indoor Cannabis Growing

If you are already settled on indoor cannabis growing, chances are you’ve already taken a gander at the different lighting options available. You may have different thoughts on the matter and different lighting systems may vary from one gardener to another. However, this article aims to provide you with the necessary information needed to help you make an informed decision well aligned with your interests.

Cannabis Light Cycle

When it comes to cannabis growth, one of the most crucial contributing factors is the light cycle. Plants rely on light to make food and energy through photosynthesis, and cannabis is no different. Luckily, light management in an indoor cannabis garden is easy. Cannabis plant follows the normal seasonal changes to grow, bloom, and seed all of which are determined by not only light exposure, but also temperature changes, and differences in relative humidity.

With indoor cannabis growing, natural growth patterns relative to sunlight exposure can be replicated since the light cycles are almost equivalent to the hours of daylight and night. During the germinating and vegetative phase, cannabis requires more light while in the flowering cycle, light exposure is often reduced, almost being equal to the amount of darkness required. By imitating nature, the techniques used to provide artificial lighting to indoor cannabis plants can be exploited to increase the yield and produce varying concentrations of cannabis elements.

More light = More Weed

Needless to say, since marijuana flowering phase naturally happens when light exposure is reduced, i.e., during winter and it is when the buds come out. We can exploit this by exposing the plants to light to boost and maintain the flowering phase to increase yield. Having a good source of light essentially means, you’ll be able to produce more weed.

Moreover, the spectrum of light you expose your plants to affect their growth greatly. With indoor cannabis growing, you can actively control the spectrums for your benefit. Take for instance the flowering phase of plants, including cannabis, utilizes the red and orange, sections of the light spectrum while growth is often controlled by the other end, the blue and indigo sections. With this knowledge, you can set your plants in varying concentrations of either spectrum section during their respective times to effectively grow marijuana indoors.

Furthermore, the period of exposure is also critical with growing cannabis requiring about 18 hours of light followed by 6 hours of darkness. During flowering phase, equal exposure time is often recommended i.e., 12 hours of light and 12 hours of darkness. Indoor growing is ideal as it lets you control over light exposure and you can choose when your “day” or “night” will occur.

Different Lighting Systems

Indoor cannabis growing requires you to set up your own lighting system and different options exist with a lot of opinions as well. Lighting systems are often categorized by their intensity, spectrum color, and the technology that made it, which will then all culminate to the size of your indoor cannabis garden, your electrical needs, and how much money and time you’re willing to invest.



In the prime days of indoor cannabis growing, fluorescent lights were used to simulate the sun. Unfortunately, these are expensive and you may require a huge number of fluorescents to simulate the sun’s power. Moreover, you also need many different fluorescent light types to mimic the full spectrum of visible light.

Presently, fluorescent lights are only used where cannabis is grown with minimal heat and need to be closer to the plants (about 5 cm). With the advent of fluorescent technology, fluorescent lights can be used more efficiently than previously deemed so. Additionally, fluorescent lights go hand in hand with reflectors which maximize their efficiency and are also energy saving.


  • HID – High-intensity discharge lights


High-intensity discharge lights were invented for huge scale use in public arenas and stadiums. HID lights are extremely powerful and work quite well for indoor cannabis growing. Under HID light, we further have different forms of this light, namely: mercury, metal halide, and sodium vapor light.

  • Mercury HID Lights. These lights are not ideal for this specific case since their lumen to watt capacity is very low.
  • MH – Metal halide lights. These produce light by passing an electric current through mercury gas mixed with a metal halide such as sodium, thallium, or thorium. The light produced falls perfectly into the cannabis growing phase color spectrum of cannabis.
  • HPS – High-pressure sodium vapor lights. These lights, contrary to MH lights, produce a light that is ideal for the flowering phase of cannabis while metal halide is superior for the growth phase. By passing an electric current through xenon and sodium gas, a dull pink glow is emitted which quickly turns orange once warmed up.

As you can see, different lights can be used together to elicit maximum effect in indoor cannabis growing.


  • LED – Light-emitting diodes


Being ubiquitous in the lighting arena, LEDs (light emitting diodes) may not necessarily be the ideal light for growing cannabis, compared to the previous counterparts. However,LED  lights provide several advantages, which include:

  • They are low voltage, thus less money will be spent on upkeep and electricity.
  • They produce very little heat, further reducing your reliance on ventilation and fans, expanding onto deeper energy savings techniques.
  • LED lighting is quieter than the other options.

Unfortunately LED lights require initial investment making it costly compared to the other options which are cheaper, but their efficiency makes them more suitable where energy saving is required and where you want to avoid thermal heat imagery. Lastly, LED lights are long-lasting, giving you quality service for a long harvest from your cannabis garden.


Indoor cannabis growing may have its challenges, but lighting is one of the easiest tasks to manage. You’ll essentially be controlling the amount and type of light to expose your cannabis garden to maximize yield and strain development. Moreover, more light exposure, mean more flowering time, and thus, more weed.

Choose the lighting option that is best suited for your cannabis growing needs and ensure you use nature as your guide.