What Watt Light Bulb to Use for Growing Weed?

When it comes to all the important factors for growing a successful cannabis plant, the most important one is the lighting. In fact, light is considered as your plant’s food.

If you don’t give your plants the right food, they can’t produce the big potent buds you are expecting. In this post, we will help you answer the question: What watt light bulb to use for growing weed? Also, we will talk about some other things you need to watch out for when shopping for a grow light for your setup.

What are Watts?

The wattage is a definition of a measure of the electrical power a grow light uses. Actually, the wattage is available in two main measurements, including the amount of electricity the light consumes and the amount of electricity it outputs.

We recommend you to choose an LED grow light because it normally outputs a high number of watts. On the other hand, it consumes relatively few. Therefore, you will have to pay for low electricity bills.

Higher Wattage is Equal to More Weed

The fact is that if you use the higher wattage of the grow light you use for your plants, they will produce more weed. For instance, if you want to grow a single plant, you will get a larger yield from a 1000w grow light compared to a 300w grow light.

How to Calculate the Wattage of Light You Need

There are two important things you need to consider when determining the wattage of light you need for your growing weed.

The number of plants you are growing

As a grower, you have to give each cannabis plant at least 1 square foot of space so it can grow in. Then, your plant also can grow to the full potential. Furthermore, you also needn’t worry about being impeded by the plants around it.

The size of your grow space

If you choose to use LED and HID grow lights for your plants, you will need the wattage of 50w per square feet of space. And, it’s about 150w for fluorescent lights.

Therefore, it’s important to calculate the square foot of the grow space if you want to calculate the wattage you need for growing weed. For instance, if you have a 2ft long and 3ft wide, you will need to get the wattage of 300w for this grow space.

PAR Output

This is a scientific term for the light wavelengths you use to grow your plants. Based on the wattage of light, you can know how the light strong. And, you will get an accurate measurement of edible light your plants are getting through PAR.

Therefore, it’s really vital to determine the PAR value than wattage when you find a grow light. Actually, you need to give your plants higher PAR values as they mature. A seeding normally requires a lower PAR value from 200 to 400 so it can thrive.

For flowering plants, you should give them a minimum of 600 PAR. It’s best to provide higher wattage with a higher PAR output.

 Most goods grows light manufacturers will offer information on PAR output. As a smart grower, you should avoid buying grow lights from any company that doesn’t offer this information.

Which Grow Light Should You Get?

If you are growing indoors, it’s best to choose an LED grow light because these lighting systems are reliable and efficient. Moreover, they also run cool and offer very effective spectrums.

If you are having from 1 to 4 plants, we recommend you to choose a 600w grow light. If there are any more than 4 plants, you should hang 2 side by side.

If you are wondering if which grow light are the best for you, I will give you 3 names of my favorite 600w LED grow lights, including Viparspectra 600w LED grow light, Phlizon 600w LED grow light, and MarHydro 600w LED grow light.


As mentioned earlier, it’s important to consider the wattage when choosing the best grow lights for your weed. However, it’s also important to pay attention to the PAR output. The best grow lights should be a great combination of high wattage, PAR, lumens, and a full spectrum of light wavelengths. Hopefully, this article is useful to you.

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