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If you’re growing cannabis indoors, you need a grow light. There are many different kinds. What’s the best grow light for cannabis cultivation? That’s a complex question, so let’s dive in.
Our Top Picks
We’ve found a range of different types of grow lights to suit any type of indoor growing.
1. BEST OVERALL: MARS HYDRO TS2000W Led Grow Light
One of the best LED marijuana grow lights.
- 704 LEDs: only consumes 150W
- Highly reflective hood: keeps all the light facing the plants, refraction angle is 120°
- 3 x 3 ft flowering stage coverage: can cover up to 4x4ft win the vegetation stage
If you’re buying new grow lights, you should get LEDs. They are energy efficient, easy to use, and don’t create excess heating issues. They have the longest lifespan of any grow light. You can change the spectrum of light they give off, meaning you do not have to change bulbs as you do with HIDs.
We selected the MARS HYDRO as our top choice because it’s a favorite among indoor growers. It comes with a dimmer switch and a set of daisy chains to hang your lights. This light covers a 3’ by 3’ area during the flowering stage, so you can use it to grow multiple marijuana plants.
One of the major advantages of LEDs is that you can control lumen output and light spectrum. This means you can use exactly the same light for a cannabis plant’s entire grow cycle without changing bulbs. MARS HYDRO sells this light as both a 2x4ft and 4x4ft light, so no matter what your grow space looks like, you can find a light that fits.
- Energy efficient
- No ballast required
- Can use the same lights for veg and flower
- Dimmer may break after a few years
2. BEST BANG FOR THE BUCK: KingLED 1000w LED Grow Lights
A full spectrum LED light for less than $100.
- Full Spectrum LED grow light: specially designed for cannabis plants, complete with handy switches for veg and bloom
- All in one design: comes with built in fans to keep it cool and quiet
- 3 year warranty: customers can return the lamp free within 90 days and send it in for professional service for the first 3 years of use
If your budget for grow light tops out at $100, this LED is a good choice. It contains a broad spectrum of lights, including ultraviolet and infrared. It can be hard to find light that hits the UV and IR spectrum.
The KingLED 1000w covers 2.5’ x 2.5’ flowering stage area, so it’s only good for growing one cannabis plant. All KingLED lights come complete with hanging equipment and a 3-year warranty. It has two switches on the side of the light, one for vegetative plants and one for the flowering phase.
The biggest issue we have with this is the naming. Calling it 1000 watt implies it has as much light intensity as a 1000 watt HID light, when it’s not. It puts out about as much light as a 400 watt HID grow light. That is perfectly adequate to grow a cannabis plant and is still a great LED grow light for people on a budget.
- Puts out about as much light as a 400w HPS bulb
- Misleading name
- Unideal switch design
3. BEST HID LIGHT: iPower 600W HPS MH Digital Dimmable Grow Light
A full HID lighting setup, complete with ballast, reflector, and 2 bulbs.
- Complete light setup: comes with ballast, reflector, dimmer, 2 bulbs, and hanging equipment
- Dual-bulb ballast: ballast can handle light output for both MH and HPS lights
- 600w dimmable light: light can be dimmed to 50%, 75% or full power
HID lights used to be the powerhouse of grow lights. Even though LEDs are taking that spot, some people still prefer HID. This setup has everything you need: ballast, dimmer, reflector, and two bulbs.
In this setup, you do not need to choose between MH and HPS bulbs. It gives you both. The MH light is for vegging the plant, and the HPS is for flowering. Thai mimics the change in natural light spectrum that occurs with seasonal shifts.
When it comes to these types of grow lights, you need to be careful with wattage. While it’s nearly impossible to give marijuana plants too much light, they can get too much heat. If these lights are not a sufficient distance from the cannabis plant, it will burn.
- Easy to use
- Covers a 3×3 ft area
- Minimal heat from ballast
- Can overheat a grow room
- Shorter lifespan than LED lights
4. BEST CFL LIGHT: SunBlaster SL0900151 13 Watt CFL Grow Lamp 4 Pack
The best grow light for seedlings or clones.
- 4 13-watt bulbs: one of the cheapest and easiest options for grow lights
- 900 lumens: enough light for seedlings, a mother plant, or small house plants
- Self-ballasted: each bulb has its own mini ballast, all you need to do is screw it into a regular lamp
There was a time when CFLs rivaled other kinds of light. Like LEDs, they are more energy efficient and cooler than HD and HPS bulbs. They also have a longer lifespan than HD and HPS bulbs. Some commercial growers preferred them in the pre-legalization days because they didn’t leave the tell-tale heat signature.
Here’s the thing, to get a CFL that is bright enough to grow a healthy plant through its full lifecycle, you need to drop a couple of hundred bucks. For that price, you might as well get an LED grow light.
That said, fluorescent grow lights still have their place. CFL grow lights are suitable for young plants. If you have a separate grow room for seedlings or a mother plant, this pack of 4 CFL bulbs should do the trick. You’ll want to move it to a bigger light once it’s ready to enter the vegetative stage
- Easy to use
- No ballast necessary
- Great for seedlings or supplemental lighting
- Not recommended for vegging or flowering
5. BEST HPS BULB: iPower 2-Pack 600 Watt Pressure Sodium HPS Grow Light
The best replacement bulbs for high intensity discharge grow lights.
- High light output: 85,000 lumen
- Long-lasting bulbs: 32,000 lit hours
- Low depreciation: Maintains 90% of output after 6,500 hours
If you’re using HID grow lights, you’ll want replacement bulbs. Sometimes the lights break, and if you can’t run to your local grow shop in time, that can spell disaster for you cannabis plants.
Everyone says you use MH lamps for the vegetative stage and HPS for flowering. In reality, an HPS light is fine for every growth stage. Flower growth is the most important part of this, so if you don’t want to bother changing bulbs, get an HPS.
Before you purchase this, make sure it fits into your grow lamp. Some lamps take double ended bulbs, these are single ended bulbs with an E39 bulb base.
- Easy to install
- High-quality bulbs
- Can save you in a pinch
- Only fit a E39 base
|BEST OVERALL: MARS HYDRO TS2000W Led Grow Light
|View on Amazon
|BEST BANG FOR THE BUCK: KingLED 1000w LED Grow Lights
|View on Amazon
|BEST HID LIGHT: iPower 1000W HPS MH Digital Dimmable Grow Light
|View on Amazon
|BEST CFL LIGHT: SunBlaster SL0900151 13 Watt CFL Grow Lamp 4 Pack
|View on Amazon
|BEST MH BULB: iPower 2-Pack 600 Watt Pressure Sodium HPS Grow Light
|View on Amazon
How we chose the best grow lights for growing cannabis
The most important factor to consider when choosing a grow light is the lit area. How big is your grow space? How many cannabis plants do you want to gorw? You might need one or two lights if you have a large area to cover.
The next thing you want to consider is light output. It’s nearly impossible to give plants too much light since no lightbulb can outperform the sun. You want to make sure you get a full spectrum of bluish light, white light, and photosynthetic active radiation for optimal growth.
You also need to think about electricity consumption and heat. This is where LED lights reign supreme. They use about half as much electricity as an HPS bulb. They also have very little heat, this has the added benefit of not needing to worry as much about ventilation. You still need air flow, but you don’t need to actively pump heat every second the light is on. This means you can have a quiet tent.
Another advantage of LED lights is because they don’t get hot, you don’t need to factor that into the optimal distance of light from the plant. You can put an LED lamp very close to the plant to mitigate stretching.
What to Know Before You Buy a Grow Lamp
There are a lot of different grow lights out there. How do you know which one is right for you? Here are some questions to ask yourself:
- What area do I need to cover with light?
- What grow phases will I be using this light for?
- Is excess heat an issue?
Types of marijuana grow lights
There are many types of cannabis grow lights, but really it comes down to HID vs LED lights. Compact fluorescent lamps can be used in separate seedling or mother rooms, but they aren’t good enough to grow a whole plant.
Light Emitting Diodes (LED)
For a long time, LEDs were for serious growers only. They used to have a high price point. Commercial farmers would invest in LEDs because they are the most energy efficient grow light out there. They also last 5x longer than HID bulbs and do not give off any heat.
These days, LEDs are much more affordable. This makes them now small-grower friendly. They’re also easy to install and don’t require a ballast.
High Intensity Discharge (HID)
HID lights are basically very powerful light bulbs. They come in two main types: high-pressure sodium (HPS) and metal halide (MH) bulbs. These are similar bulbs that use different elements to give off slightly different spectral outputs. Most people use the MH bulb for vegging and HPS for flowering, but if you only have one, use the HPS.
All HID lights need a ballast. This is a box that regulates the energy going through the lamp, it lets you dim and brighten the bulb. They don’t last as long as LEDs, they use more electricity, and they give off heat. That said, some growers in colder climates find them useful for maintaining a “tropical” grow environment.
That said, most people who use HID lights have issues with the heat. You need to keep your plants a fair distance from the light because if they get too close, you can burn your plant. HID lights also do not last as long as LEDs. They are also more prone to break mid-grow, which can result in disaster if you do not replace the bulb fast enough.
Compact Fluorescent (CFL)
Compact fluorescent lights come in many different styles. You’re probably familiar with spiral CFL bulbs. There are CFL bulbs that screw into normal lamp fixtures. There is also T5 fluorescent lighting which is a big straight tube. T5 lights used to be fairly popular because, like LEDs, they are cooler and more efficient than HID lights. However, they aren’t as bright as HID lights and also require a ballast, so we don’t recommend T5 lights.
CFL lights have mainly fallen out of fashion now that the price of LEDs is falling. That said, they are the cheapest type of bulb. Many people like to use 4 CFL bulb lamps as a supplemental light or for a seedling room.
CFL lights have their place in a grow operation, but we don’t recommend growing a whole plant with them.
There’s a lot to be said about spectrums and radiation but at the end of the day, you just need bright light. HID and LED lighting have enough output for veg and bud production. CFLs are good for seedlings.
For most small scale indoor cannabis growers, a 600w HPS or 1000w LED will work. You can always buy a bigger light.
How much light a plant can use isn’t just about wattage. The light needs to be directly over the plant so it can get the maximum photosynthetic energy.
This is where you want to consider the overall shape of your light. If you have a longer and thinner growing area, you can get a bar light. Bar lights are also good for rows of plants. Square lights are better for square growing tents.
There’s two factors at play when it comes to keeping your lights on: energy consumption and lamp lifespan. LED lights use about half the electricity and can stay on for about 5 times as long as HID.
That said, there is one downside of LED grow lights. They are less modular than HID. If something on your HID setup breaks, you can replace that single part. When one part of your LED grows light breaks, you must replace the whole thing.
Tips for using grow lights when growing weed indoors
Don’t forget your ventilation! Even if you’re using LED grow lights, you need to keep air moving. With hotter lights, it’s even more important to keep everything cool.
Make sure to hang your lights at the optimal distance. For an HPS bulb, that’s at least 18 inches, ideally not more than 24. You get more flexibility with LED lights, but it’s best practice to keep them a minimum of 6 inches away from the plant.
- Buy lights in the shape of your space
- When in doubt, use lights for flowering
- CFLs are for seedlings only
You’ve got questions about grow lights, we’ve got answers.
Which type of grow light is best for growing cannabis?
LED grow lights are the best choice for most growers. They are powerful, energy-efficient, and do not create excess heat.
Which type of grow light is the cheapest?
CFL lights are the cheapest, but they’re just not great. LED grow lights have massively decreased in price in the last few years. They are the most cost-effective grow lights on the market.
What’s the difference between HID, HPS, and MH lights?
High pressure sodium (HPS) lights and metal halide (MH) lights are different types of high-intensity discharge (HID) bulbs.