What Kind of Lights Do You Need to Grow Cannabis?

Learn what kind of lights you need to grow cannabis, including the different types of lights and how they affect your plants.

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Different Kinds of Lights

When it comes to growing cannabis, there are a few things you need to take into account. One of the most important things is the kind of light you use. Different kinds of lights will produce different results. So, it is important to choose the right light for your needs. In this article, we will be exploring the different kinds of lights that you can use to grow cannabis.


Incandescent lights are probably the type of light that you’re most familiar with. They’re the traditional light bulbs that have been around for years. These lights produce light by heating a filament inside the bulb. While incandescent lights are very cheap, they are not very efficient. A lot of the energy that they use goes into producing heat instead of light.

While incandescent lights can be used to grow cannabis, they are not the best option. Cannabis plants need a lot of light, and incandescent lights just don’t produce enough light to be effective. They also produce a lot of heat, which can be bad for your plants. If you do decide to use incandescent lights, make sure to get ones that are specifically designed for growing plants. These bulbs will produce more light and less heat than regular incandescent bulbs.


Fluorescent lights are the most energy efficient and have a very long lifespan. They come in two shapes: tubular and compact. T5, T8, and T12 are tubular fluorescent lights that differ in their diameters. T5s are the smallest and most efficient while T12s are the largest and least efficient. CFLs or Compact Fluorescent Lights are small, screw-in bulbs that come in a variety of wattages and sizes. While they aren’t as efficient as T5s, they’re much more affordable, replacement bulbs are easy to find, and they emit very little heat.

What to Look for When Buying Lights

When you’re looking for lights to grow cannabis, you’ll want to know what to look for to get the best results. The type of light, the intensity, and the spectrum are all important factors to consider. In this article, we’ll go over all of the different types of lights and what they’re best for so that you can make the best decision for your grow.


The wattage of your light is going to be one of the most important factors in determining how well your grow room will do. Wattage is a measurement of how much light the bulb emits. The more watts, the more light. But, it’s not that simple. Different types of lights emit different intensities of light. So, a 100-watt LED light might be more powerful than a 150-watt HPS light. It all depends on the type of light and how it’s made.

To get an idea of how much light you need, you can use this rough guideline:

-For seedlings and clones: 20-40 watts per square foot
-For vegetative growth: 40-60 watts per square foot
-For flowering: 60-150 watts per square foot

But, again, it all depends on the type of light you’re using. So, don’t take these numbers as gospel. Just use them as a starting point when you’re figuring out your lighting needs.

Kelvin Rating

The Kelvin rating is a measure of the color of light, and it’s important to cannabis growers for two reasons. First, different stages of plant growth require different colored light, and second, because different colors of light can have different effects on the final product.

Cannabis plants grow best under full-spectrum light, which includes all the colors of the visible spectrum. Sunlight is full-spectrum light, but unfortunately, it’s not strong enough to grow healthy cannabis indoors. That’s why grow lights are necessary.

Grow lights are available in a variety of colors including blue, red, white, and yellow. The color of light you need depends on what stage of growth your plants are in. Blue light is necessary for vegetative growth, while red light is needed for flowering and fruiting.

Kelvin ratings indicate the color of light emitted by a grow light. The higher the Kelvin rating, the blue the light appears; the lower the rating, the redder the light appears. For example, a 2700K bulb emits a warm yellowish-orange light similar to an incandescent bulb, while a 6000K bulb emits a bright bluish-white light.

To ensure your plants get the right amount of full-spectrum light at each stage of their growth cycle, you need to choose grow lights with a Kelvin rating that corresponds to their needs. These needs vary depending on what you want to grow:


Lumens measure the amount of light that is emitted from a certain area. One lux is equivalent to one lumen per square meter. The higher the lumens, the brighter the light. For example, a 100-watt light bulb emits about 1,600 lumens.

How Many Lights Do You Need?

To get a better understanding of how many lights you need, you need to understand the different types of lights and how they affect your cannabis plants. The type of light you use will also affect how much heat is produced. With that being said, let’s take a look at the different types of lights.

Square Footage of Grow Space

The size of your grow space will have a big impact on how much light you need to support healthy plant growth. A general rule of thumb is that you should provide about 32 watts of light per square foot of grow space. So, if you’re growing in a 4x4 area, you’ll need at least 512 watts of light. But, this is just a general guideline. The amount of light your plants actually need will vary depending on the type of plants you’re growing, the stage of growth they’re in, and other factors.

Number of Plants

The number of plants you can grow in your space depends on a few factors. The average 4’x4′ grow tent can hold 8-16 plants, but more space is always better. If your space is limited, it’s best to grow fewer, larger plants. If you have more space, you can grow more plants and keep them smaller.

The type of lights you use also affects how many plants you can grow. For example, if you’re using HPS (high pressure sodium) lights, you’ll need to keep your plants further apart to prevent them from getting too much light. With LED (light emitting diode) lights, you can keep your plants closer together because they produce less heat and don’t require as much ventilation.

Ultimately, the number of plants you grow will be determined by the amount of space and the type of lights you have. Start with a few plants and increase the number as you become more comfortable with growing cannabis.

Tips for Using Lights

The type of light you use to grow cannabis can have a big impact on the quality and quantity of your crop. Different lights can produce different results, so it’s important to do your research and choose the right one for your needs. In this article, we’ll give you some tips on choosing the right light for growing cannabis.

Mount Lights Properly

To ensure your lights are providing the optimal amount of light, it is important to mount them correctly. The higher you can get the light off the ground, the better, as this will prevent your plants from getting too close and being damaged. When growing indoors, you will also want to make sure your lights are not too close to the walls as this can reflect light away from your plants.

Keep Lights Clean

Cannabis plants are light hungry and need a lot of it to grow properly and produce bountiful harvests. But not all lights are created equal, and each type has its own benefits and drawbacks that you should be aware of before making a purchase. In this article, we will discuss the different types of lights available on the market and their pros and cons. We will also provide some tips on how to get the most out of yourlights

There are three main types of lights used to grow cannabis: fluorescent, metal halide (MH), and high-pressure sodium (HPS). Each has its own advantages and disadvantages that you should take into account before deciding which is right for you.

Fluorescent lights are inexpensive, cool to the touch, and emit very little heat, which makes them a good choice for small grow spaces. They are also very energy efficient. However, they provide less light per watt than MH or HPS lights and need to be replaced more often.

Metal halide lights emit more light per watt than fluorescent lights but generate significantly more heat. They should only be used in well-ventilated spaces or with proper ventilation and cooling setups. MH lights also require regular bulb changes.

High-pressure sodium lights are the most efficient type of light for cannabis growers. They emit a lot of light per watt and do not need to be replaced as often as fluorescent or MH bulbs. However, HPS lights produce a lot of heat and require proper ventilation to prevent damage to your plants.


Now that you know the different types of lights available to growers, you can make an informed decision on what will work best for your grow room. Keep in mind that each type of light has its own benefits and drawbacks, so find the one that best suits your needs. If you have any questions, don’t hesitate to ask a professional for help.

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