What Kind Of Light To Grow Weed Indoors?

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So, you want to grow weed indoors, but you first need to buy the equipment. Yes, there are a few things you will need to grow weed indoors, with the light being one of the most important components. You will never be able to grow marijuana indoors without a half decent light.

So, What kind of light to grow weed indoors should you use? Well, there are 3 different kinds of lights which can be used to grow weed indoors. This includes the LED light, the HID light, and the good old fluorescent light.

Which type of light you use for your own indoor marijuana grow op is your choice, but beware that each comes with specific benefits and drawbacks.

Let’s take a closer look and help you decide what is the best light to grow weed indoors for you.


1. LED Lights

One type of light which many growers choose to go with is the LED light. When it comes down to it, LED lights tend to be some of the cheapest kind of grow lights to buy, except for some fluorescent lights, which can be even cheaper.

One big advantage of newer LED lighting systems is that they feature great light penetration, which means that the light from these bulbs can reach all parts of your weed plant, and unlike fluorescent lights, they do not need to be moved around very much.

Moreover, and other advantage that comes with using LED lights for growing weed is that they tend to run fairly cool, and usually always come with some kind of built in cooling system. They allow for fairly high yields, yet unlike HID lights, they usually do not require a separate ventilation or cooling system.

There is also the fact that LED lights are very easy to set up. For the most part, you can just hang them over your marijuana plants, plug them in, and they are good to go. Also, LED lights tend to be fairly energy friendly.

In the grand scheme of things, LED lights do not come with a huge startup cost, and if done right, they should not jack up your electricity bill too much either.

Keep in mind that an LED grow light will produce a higher yield per watt than a fluorescent light, but usually always less than an HID grow light.

LED Light Pros

  • One big pro of LED lights is that they usually always come with built in cooling systems which pushes the heat up and away from the plants. They tend to run fairly cool, and for the most part, growers can usually manage without a ventilation system. They run much cooler than HID grow lights.
  • Most of the smaller LED grow light systems can just be hung up over your weed plants, plugged in, and they are ready to go. In this sense, they are very user friendly.
  • Many growers like using LED lights because they produce really resinous bud and tend to produce a higher yield than fluorescent lights. A popular option is to use a combination of LED and HID grow lights.
  • In the grand scheme of things, they are not all that expensive to buy.

LED Light Cons

  • One problem that you will notice with LED lights is that they need a lot of clearance between the bulbs and your pot plants. This means that you generally need a very tall growing area, because even smaller LED lights need around 18 inches of space between the lights and the plants.
  • Larger LED grow lights may need to be kept up to 30 inches away from your plants. The problem has to do with the LED lights burning your buds if they are too close.
  • Now, LED lights do run a lot cooler than HID lights, but beware that larger bulbs, such as 300 watts or more, will still produce a decent amount of heat, and thus may require a ventilation system. It’s something to keep in mind if you want a really powerful LED setup or have a lot of plants.
  • LED grow lights, while they produce better yields than fluorescent lights, do not produce as high a yield as HID grow lights do. You can expect an LED grow light to produce around 0.5 grams of bud per watt.

Final Thoughts On LED Lights

LED Lights for growing are great if you have a tall grow room, if you want a really easy setup, low energy costs, and a fairly decent yield.

If you want to harvest about 1 ounce of cannabis per month, a beginner LED setup will do just fine. One thing to keep in note here is the light spectrum.

You need to get an LED grow light which also includes green and white light, not just red and blue. It needs to be a full spectrum LED light.

2. HID Lights

The next type of light that is often used for growing weed indoors is the HID light. HID stands for high intensity discharge, and as you can probably tell by the name, they put out a whole lot of light.

When it comes to pure yields, HID lights are undoubtedly the best option to go with, as they will produce much better yields than both fluorescent and LED lights.

However, HID lights are hard to set up, as there tend to be a few different components that are required. HID grow lights also run very hot and usually always require a separate ventilation cooling system to deal with the excessive amount of heat which they produce.

Due to the high intensity of light output from HID lights, they tend to have high electricity costs, not to mention that they cost a lot to buy in the first place, even for smaller ones.

Keep in mind that this is not a grow light you would get as a beginner, or if you are only growing 1 or 2 plants. Yes, they do cost a lot, and take effort to set up, so they are not the best for first time growers.

However, if you have some experience and a bit of extra cash to spend, you have a few plants and want the highest yields possible, the HID grow light is the best way to go.

Now, there are 3 different kinds of HID lights for growing weed indoors, so let’s take a quick look at each of them.

A. Metal Halide

The first type of HID light that you can go with for growing cannabis is the metal halide light.

These generally produce a bluish light from the blue light spectrum, and are therefore best used for the vegetative state of weed plant growth.

This kind of HID light can also be used for the flowering stage if necessary, but it is not 100% ideal for this purpose.

B. High Pressure Sodium

Next, you have your high pressure sodium HID grow light. The high pressure sodium light, unlike metal halide lights which produce mostly blue light, the HPS lights produce mostly yellow light.

For this reason, the high pressure sodium light is best used for weed plants in the flowering stage, as it helps to spur on bud and THC production.

The bottom line is that if you use one of these HPS lights during the flowering stage of your plant, you will get better bud yields than with any other kind of grow light out there right now (we have reviewed our favorite HPS lights here).

C. Ceramic Metal Halide

Ceramic metal halide HID grow lights sit in the middle of the other two which we have looked at. These bulbs are more efficient and powerful than metal halide bulbs, but less so than high pressure sodium bulbs.

HID Light Pros

  • When it comes down to it, HID grow lights produce the best results, the highest THC content, and the best yields. If you are going for high yields and great quality, the HID light is the way to go. You can expect between 1 and 1.25 grams of bud for every watt which your HID light puts out.
  • What is nice about HID lights is that there is not much guesswork involved when hanging them up. For one, they can be hung the right distance from your plants with ease, using a wattage to distance chart. Moreover, unlike fluorescent grow lights, they do not always need to be moved around and adjusted for distance.
  • If you want to get really nice results, this is the way to go. As we noted above, metal halide lights are best for vegetation, and high pressure sodium lights are best for flowering. If you are serious about growing weed, you will want to get one of each for the respective growth stages.

HID Light Cons

  • HID lights require quite a few parts, which makes the setup a bit difficult. Generally speaking, you will need the bulb, the fixture, an external ballast, the power cable, and yes, some kind of ventilation or cooling system too. These things are hard to set up and are therefore best reserved for serious growers.
  • HID bulbs are expensive to buy, and here we are talking about the bulbs alone, but of course, all of the extra stuff you need is just going to add to the price. These things cost a whole lot to purchase and they use a ton of electricity. If you are worried about power costs, HID lights are not going to be your best friend.
  • HID lights get really hot and they produce a whole lot of heat, which is not good for your plants or for the grow room in general.
  • Any HID light above 200 watts is going to require a separate and external cooling system. At the very least, you will need a hood for the bulb, as well as some kind of half decent fan or ventilation system to stop the ambient temperature in the grow room from skyrocketing.

HID Grow Lights – Final Thoughts

So, there is no arguing the fact that the HID grow light is your number one choice when it comes to big yields and high quality buds, especially if you use an MH light for the vegetative stage and an HPS light for the flowering state.

Yes, these things are expensive to buy and they use a lot of power, plus they need a bit of work to set up, but when all is said and done, they do produce the best results.

Due to the price, it’s not something we would recommend if it is your first time growing weed, if you only have 1 plant, or if you are on a limited budget. Just as a little example, a 250 watt HID light is going to cost you around $600 to purchase, around $70 per month for electricity, and will produce yields of around 2 ounces per month.

Stepping things up a bit, a 600 watt HID light will cost around $800 to purchase, $130 per month for electricity, and will produce yields of 5 ounces per month.

3. Fluorescent Lights

The third and final type of grow light that you can use for your indoor grow operation is the good old fluorescent light. Fluorescent grow lights are not the number one choice to go with in terms of yield and bud quality, but they do come with certain benefits none the less.

These fluorescent lights come in many different shapes, lengths, and sizes, which is one big benefit. Moreover, if you are growing in an open space, fluorescent lights are not as hard on the eyes as either of the other types of light we have looked at today.

Fluorescent lights are very easy to hang up. You really just have to buy them, hang them right above your plants, plug them in, and they are good to go. There is hardly any work involved here, and you really do not have to make any special calculations in terms of the distance from the light to the plants.

Fluorescent lights are the cheapest of all grow lights to buy, and they also do not use much power, thus cutting down on electricity costs. However, in terms of yield, they undoubtedly produce the worst results out of the 3 types of grow lights examined here today.

There are two main types of fluorescent lights used for growing weed, these being compact fluorescent lights, or CFL for short, and T5 grow lights, which are those long tubes you might be familiar with, you know, the ones that flicker in creepy old basements.

A. Compact Fluorescent Lights

CFL lights are those classic spiraled lights that you probably have somewhere in your home. They are convenient because they can be found pretty much anywhere you would usually buy light bulbs, and they barely cost anything to purchase, plus they are quite energy efficient too.

These are fine for a couple of plants because they do not take up much space and work great in really small areas where other light types just cannot fit, either due purely to size, or because of the distance needed between the bulbs and the plants.

These are usually full spectrum lights, so they can be used both for marijuana vegetation and for flowering. You do need to keep these really close to the plants for the best results.

B. T5 Grow Lights

T5 grow lights, or other T5 light fixtures, are those long fluorescent tubes. You have probably seen these before, as they are often used for commercial lighting and other such purposes.

They are available in most home and garden stores, construction stores, and home improvement stores. Of course, these are much bigger and wider than normal CFL lights, so they do take up quite some space.

However, they often come with 2, 3, or 4 fluorescent light tubes in a single fixture, therefore making them fairly ideal if you are growing more than 1 plant, or if you just want the maximum light output possible for the lowest cost.

Fluorescent Light Pros

  • By far, fluorescent lights are the cheapest to buy out of all grow lights. They also tend use the least electricity, thus making them extremely cost effective.
  • Unless you have a whole lot of them packed together in a tight space, fluorescent lights do not produce very much heat at all, and therefore rarely require any special kind of ventilation or cooling systems.
  • Fluorescent lights have a fairly good light spectrum output for growing weed plants, and all kinds of plants for that matter.
  • Fluorescent lights, due to their limited output and limited heat which they produce, can be kept just a couple of inches from your plants, and therefore work well if you want to grow weed in a really tight space.
  • These are great for small plants, young plants, clones, and such, as they do not use much power and you don’t run the risk of burning your plants with them.

Fluorescent Light Cons

  • Fluorescent lights just do not produce very great yields. Yeah, you can still expect a couple of ounces per month, so to speak, but it is nothing compared to the yield you will get from an HID light.
  • Every watt of electricity put out by a fluorescent light will produce roughly 0.25 grams of bud, which is half as much as an LED light can muster, and about a quarter as much as an HID light can muster.
  • Fluorescent lights do not have very good penetration power, which means that they are not ideal for flowering or for tall plants. Their light does not penetrate deep, and therefore works best as supplemental lighting, for small and flat plants, for seedlings, and for clones. It is not like you cannot use them for flowering, but they really are not the best.

Which Type Of Grow Light Is Best For You?

There you have it guys, the 3 types of lights you can use to grow weed, what they are all about, their benefits, drawbacks, and more. When it comes down to it, if you have some cash to invest and you are serious about getting great bud and lots of it, there is no better option to go with than an HID grow light setup.

If you want something very cost effective that is easy to use and comes with limited issues, fluorescent lights are the best, but just keep in mind that they also produce the lowest yields. So, when all is said and done, we might just recommend LED lights for your average indoor grow operation, as in terms of ease of use, cost, and yield, they sit more or less in the middle between fluorescent and HID lights.

We have also covered a guide on light schedules here which you might find helpful.


My passion for the sticky icky started nearly a decade ago, and it all began when I first laid my eyes on the beauty that is the marijuana plant.

I cover all aspects of growing from equipment recommendations to plant health/care tips to help both new and experienced growers.