Grow Lights For Marijuana Plants

Grow Lights For Marijuana Plants
Grow Lights For Marijuana

Growing marijuana indoors is completely different from growing outdoors. In terms of your setup, indoor growers have full control over the environment of their plants. With this ability to adjust almost every aspect of cannabis growing, you can produce higher-quality marijuana than you could outdoors!

However, this ability almost like a double-edged sword. Unlike outdoor growers that have the sun as the main provider of light for their plants, indoor growers need to install grow lights. Knowing which grow lights for indoor plants to choose can be a challenge. If you like to know the best grow lights for indoor plants of the cannabis variety, continue reading!

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There’s a difference between your standard lights and grow lights. You can’t simply use an A-series light bulb and expect it to be enough for your marijuana to flourish!

The grow light that provides both types of UV is high-intensity discharge bulbs or simply HID. They’re the most commonly used type of cannabis grow light because they provide the best spectrum of light for your cannabis’ vegetation phase and its flowering phase.

hid high intensity discharge lamps marijuana
A high-intensity discharge bulb (HID)

On the other hand, an MH (Metal-Halide) lamp provides the best light for your plants in their vegetation phase, while HPS (High-pressure sodium vapor) lights are best during the flowering phase. However, HIDs are quite expensive and aren’t beginner-friendly. Thankfully though, there are other indoor grow light options for your plants!

The Best Indoor Grow Lights for Plants

Outside of HIDs, other types of grow lights for indoor plants can also work for marijuana. Some of them even offer better quality features than HIDs. Here are three other potential grow lights for weed plants:


Incandescent grow lights
Incandescent grow lights

This is your standard light bulb. Although you’d typically use incandescents to illuminate your home, they also work as grow lights. Incandescent lighting is usually the first option people consider as they’re cheap and easy to replace. However, I  do not recommend them for several reasons.

  • Incandescent lights are inefficient and consume more power than other types of lights. 
  • You’ll need to pay attention to placement because they’ll easily burn your plants. 
  • They burn out fast, and you will need to replace them often. 



Fluorescent grow lights_T5 bulbs
Fluorescent grow lights – T5 bulbs

A step up from incandescent lights, first-time growers may do well with fluorescent lighting. They use a lot less electricity which means you’ll save on energy, and they don’t generate a lot of heat that will burn your plants. Fluorescent lights also come in two types, the T5 bulbs, which are suitable for larger gardens, and CFL bulbs, which are best with smaller indoor setups. However, fluorescents aren’t perfect. They, too, have their drawbacks, such as: 

  • A limited light output, meaning you’ll only grow a maximum of 1-2 plants per bulb.
  • Low yield potential

For these two reasons, I recommend saving them for a single autoflower grow or when hardening seedlings for outdoor growing.


LED grow lights
LED grow lights

If you want a quick and easy setup like fluorescent lighting as well as high-quality lighting like HIDs, you should consider LED grow lights for indoor plants. Unlike HIDs, which take some time to warm up, LEDs immediately provide the amount of heat and light the moment you turn them on. They also stay “cool to touch” as LED lights barely produce any heat.

LEDs are also the most energy-efficient type of grow light to have as a grower, meaning you’ll save money in the long run. However, they’re quite expensive – more so than HIDs. However, it’s entirely worth it as trying to cut corners by buying cheaper models will produce subpar results.

Factors to Consider When Choosing Cannabis Grow Lights

For the fastest growth, choose HID.

As I’ve already established, HIDs are by far the overall best choice of grow lights for weed plants. They encourage faster growth by using different colored temperatures and generating the preferred UV light for cannabis plants.

They also cater to different stages of growth. This is particularly the case when you use an MH lamp for vegetating and an HPS for flowering. That means two separate lights – an MH lamp generating a cool white light and an HPS giving off a yellow or red visible light. Because of the need for multiple lights, HIDs are perfect for larger-scale cultivation. Around 20+ high-potency auto-flowering plants grow comfortably under HID lighting.

Looking for easy-to-grow marijuana? Go for autoflowering cannabis seeds! You don’t need to worry about complicated light setups, plus, they grow fast – which can lead to more harvests. Explore our wide selection of autoflowering seeds in our shop.

Buy Autoflowering Seeds

One thing to take note of, though, is the heat that HIDs generate. Not only because they may end up burning your plants, but the lights themselves may overheat and burn out faster. So, replacement bulbs are something to keep in mind.

The different parts of an HID cannabis grow setup
The different parts of an HID cannabis grow setup

More lights mean more heat.

And on the note of heat, the number of grow lights can affect how much heat there will be in your grow room. There are ways to counter this, such as using fans and implementing a proper ventilation system, but we’ll get to that sooner.

For now, it’s important to consider the number of lights you will need for your plants and the problems of having too much. Again, too much light can cause complications for your cannabis plants. 

If you don’t want to worry about these things, choose LEDs as they don’t produce as much heat as HIDs or Fluorescent lights.

More lights mean more heat - choose LED grow lights
If you don’t want to worry about too much light or heat, choose LED grow lights

Lights run on electricity.

Having to keep the lights on for your growing cannabis will slowly accumulate cost in the form of your electricity bill. It’s crucial to be conscious of the cost of keeping your grow lights on if you’re growing your own marijuana to save money.

Cannabis requires 18 hours of light during their vegetation phase and 12 hours in their flowering phase. The thought of keeping lights on for that long may deter many first-time growers. However, it’s important to remember that the type of light will ultimately affect the cost of keeping them on. LEDs and Fluorescent lights are the cheapest to leave on.

Tips on Using Grow Lights for Marijuana

I mentioned how putting an incandescent light too close to a plant can burn them, but this issue applies to every type of light. Just more so with incandescent. As a grower, you need to know how to properly install, place, and use grow lights. Here are three tips that’ll help:

Use a grow tent

Use a grow tent
A grow tent

For the best results, use a grow tent as part of your indoor setup. Sure they are an added cost, but the benefits a grow tent provides makes it worth it.

Grow tents help keep light within the space and reflect the light from your grow lights onto your weed plant. This ensures every part of your plant receives evenly distributed light. Another benefit of a grow tent is its controlled environment. Even though your lights may increase heat within the tent, you can easily regulate temperature and humidity. Grow tents are also highly durable and can last for many years, which lets you reuse them repeatedly.

Use fans

Use fans
Use fans to control temperature and humidity in your grow room

Speaking of controlling temperature and humidity, fans are a must-have. For one, they encourage good air circulation, letting fresh air continuously stream into your grow area. Trust me; your cannabis plants will thank you for it. 

Fans also prevent stagnant air and help control the heat around your grow area. This is important for discouraging pathogens and pests. The air from fans also introduces an element of stress for your cannabis that encourages them to grow sturdier as the fan blows air against them.

Follow a lighting schedule.

Follow a lighting schedule
Follow a proper lighting schedule

Lastly, growers should always follow a proper lighting schedule. Even if you are growing autoflowers, sticking to a schedule helps you avoid wasting energy and ensures your plants aren’t overexposed to light.

Overexposure to light can burn your plants or stress them out, which will cause them to hermie (turn into hermaphrodites). And in the case of flowering plants, it can force them back to their vegetation phase. This is why being meticulous about the hours of light and darkness your plants get is important, not just for saving money but also for saving your plants. 

Here’s my guide on lighting schedules.

Cannabis lighting can be complicated, but it isn’t impossible. You simply need to learn a little about your options and choose the best lighting for your situation. Even if you get it wrong, you’re likely to end up with something. 

As long as you don’t burn your plants. 

Which grow lights have you used on your cannabis plants? Please share your experience or leave questions in the comments.

Happy Growing!


FAQs About Grow Lights

Can any LED light be used as a grow light?

As long as the type of LED you’re looking into produces the amount of light that your cannabis needs, you can use any LED light. However, serious growers should stick to cannabis grow lights for the best results in their indoor garden.

Can you leave grow lights on 24 hours a day?

In the case of auto-flowering cannabis, yes, you can. However, there is some debate on whether or not 18 hours or 24 hours is ideal. Since I only sell the best genetics, my autoflowers can safely receive 24 hours of light, maximizing your harvest and saving you from having to set a timer.

What is the full spectrum of LED grow lights?

LEDs cover all three types of UV light (UVA, UVB, and UVC). They also cover the visible spectrum of light as well as infrared light. In layman’s terms, a ‘full-spectrum light’ means it closely resembles light from the sun.