What Light Do You Use To Grow Weed

Growing weed may sound like a simple thing to do, but it is easier said than done. When you want your indoor plant to have buds exploding out of it, you need to take real good care of it. Providing the perfect light condition for growing weeds is one of the most essential aspects of cultivating cannabis.

Light is the main ‘food’ of plants and unless it gets enough food, the plant won’t produce enough buds. As a result, grow lights are extremely important for growers who are interested in indoor cultivation. In this article, we will answer the most frequently asked question by new growers, and that is – what light do you use to grow weed?

To be specific, growers can use three different kinds of lights to grow weed and these are Fluorescent Grow Lights, High Intensity Discharge (HID) Grow Lights, and LED Grow Lights. We will discuss each one in detail below.

Fluorescent Grow Lights

The fluorescent grow lights are perhaps the oldest and most popular type of grow lights used for weed cultivation. They come in a variety of shapes and sizes ranging from long tubes to twisted bulbs. The light they produce are pleasant to the eyes and they are energy efficient too. It works perfect for herb gardens and small budget indoor gardening without paying high electricity bills. The fluorescent grow lights are of two different types – CFL Grow Lights and T5 Grow Lights.

The CFL grow lights are the twisty shaped bulbs that you can find at any electrical store. They take less space and produce an amazing spectrum of light that is favorable for weed growth. They can easily fit inside any cabinet where you may not be able to use other traditional lights.

The T5 grow lights are one of the most easily available and you can find several types of them suitable for different kinds of plants. You can find T5 lights in stores selling home improvement and garden products. These lights are wider and bigger than CFL lights for growing weed.

Benefits of using fluorescent lights

  • They are comparatively cheaper
  • They are suitable for seedlings, clones and young plants
  • They don’t need a lot of electricity to produce light
  • The heat produced is not very intense unless you have many CFLS bunched together

Downsides of using fluorescent lights

  • They get smaller yield per watt
  • Not powerful for flowering stage in taller plants

High Intensity Discharge (HID) Grow Lights

These are the more professionally made grow lights specifically made for that purpose. These bulbs are odd shaped and they are much more powerful than their fluorescent counterparts.  They usually come with a reflector or hood which helps in reflecting more light to the plants below. The HIDs provide as the most favorable environment for maximum weed growth. However, it tends to make the inner temperature very hot hence you need an exhaust to vent out the heat.

There are mainly three different types of HIDs we know – Light Emitting Ceramic (LEC) grow lights, Metal Halide (MH) grow lights, and High Pressure Sodium (HPS) grow lights.

High Pressure Sodium (HPS) grow lights are yellow colored and they stimulate the production of buds like none other. When used in the flowering stage, they provide a much better yield per watt compared to other lights. Growers prefer this type of light particularly for the flowering stage.

Metal Halide (MH) grow lights produce a bluish light which the plants really love. This type of light is best suited for the vegetative stage. It can be used in almost all stages, until the harvest of plants.

Light Emitting Ceramic (LEC) is also known as Ceramic Metal Halide (CMH). They are a variety of metal halide bulb which uses ceramic as an essential part of the bulb. They are considered as more energy efficient than the traditional Metal Halide lights.

Benefits of Metal Halide (MH)

  • They give you the highest yield per watt
  • They are highly efficient and used mainly for the flowering stage
  • They are simple to use as these lights can be hung correctly without any stress

Downsides of Metal Halide (MH)

  • The bulbs tend to get too hot
  • They produce a lot of concentrated heat
  • You needs a cooling system as the light bulb produces too much heat
  • It requires additional set up which adds up to total cost

LED Grow Lights

The LED grow lights are looked upon as a cost effective and efficient alternative to the HPS (high pressure sodium) grow lights. They come with an inbuilt cooling system hence this light runs cool. They can either be fixed to the wall or hung over the plants. Just as you desire.  The LED lights further have a higher level of penetration so that means you don’t need to move the fluorescents frequently.

When buying LEDs you must ensure that they have some amount of green or white light. If it has only red and blue light then better don’t get it. Plants that are grown without green or white light usually have nutrient deficiencies.

Benefits of LED Grow Lights

  • They have built-in cooling systems that do not let the temperature get too hot
  • The small LEDs can be easily mounted on wall or hung over the plants
  • LED light helps in producing better quality buds

Downsides of LED Grow Lights

  • Bigger sized LEDs may need to be vented with an exhaust fan
  • They produce less yield per watt than other lights
  • They need a lot of space between lights and plants so you need tall growth space


We hope the information provided here answers your question – what light do you use to grow weed. To sum it up, there are three main types – fluorescent lights, metal halide and LED lights. If you are new in this business and you want to start with a small patch then we would suggest you go with fluorescent lights to keep your budget low. If you are hoping to cultivate more weed, we would recommend metal halides for effective growth and LEDs for good return for investment.

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James Alexander James Alexander
Hey, I'm James! The founder and head writer here at GreenBudGuru.com. I started this site to share my passion and knowledge of all things cannabis. I used to work as a budtender in central Amsterdam, and have over 7 years of growing experience.

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