You often hear about growers trying to decide between HPS/MH and LED grow lights. But what about ceramic metal halide grow lights? The truth is CMH grow lights have increased in popularity over the years, and there are a couple reasons for that.
For starters, a CMH bulb offers an even light spectrum that’s good for both the flowering and vegging stages of plants. In addition, CMHs are able to pump out major light intensity with relatively low energy consumption. The end result is an effective light that’s powerful enough to get your plants through different stages without impacting your electric bill too heavily.
With so many options out there, though, it can be difficult to decide on the best CMH grow light for you. That’s why we’ve tested a variety of CMH grow light kits — to provide you with the details necessary to make an informed decision. We want to make sure you’re prepared to find the best CMH grow light regardless of budget or skill level.
Table of Contents
- What is a CMH Grow Light?
- The Benefits of CMH Grow Lights
-
The Best CMH Grow Lights of 2020
- A CMH Grow Light Is a Great Choice for Your Grow Room
Before you help you decide between the best CMH grow lights on the market, though, let’s take an in-depth look at what makes ceramic metal halide grow lights so effective.
What is a CMH Grow Light?
As its name suggests, a ceramic metal halide grow light uses a ceramic arc tube as opposed to a standard MH grow light, which uses a standard quartz arc tube. This stronger arc tube material helps the CMH bulb operate at a much higher pressure than the average MH bulb.
Like HIDs, CMH grow lights use a unique mixture of salts and halides to provide a ranged spectrum of light. The ceramic arc tube of the CMH bulb slows down the caustic breakdown of this mixture, creating a broader spectrum that gives plants enhanced photosynthesis for optimum growth.
CMH Grow Lights vs. HPS and MH Grow Lights
A CMH bulb offers a more natural-looking light spectrum than the bright light you’d get from an HPS or MH bulb. This light can be measured (and compared) using the Color Rendering Index (CRI). For comparison’s sake: 
- The CRI of the sun is 100.
- The CRI of an HPS bulb is 20 to 30.
- The CRI of an MH bulb is 60 to 64.
- The CRI of a CMH bulb is 90 to 92.
As you can see, the Color Rendering Index of a CMH bulb is pretty similar to what the sun offers. This means a CMH grow light will give your plants a spectrum of light that comes close to what sunlight offers naturally.
The Benefits of CMH Grow Lights
If you’re looking for a strong, versatile, and efficient light, you should consider a CMH grow light kit. Using CMH grow lights in your indoor grow room or grow tent is beneficial for many reasons:
- CMH grow lights provide a broad spectrum. Because CMHs mimic the sun, your plants receive a broad spectrum of light.
- Your plants will receive UV light from these grow lights. Ultraviolet light offers your plants many benefits. These include faster photosynthesis for plant growth, increased flavor, and better pest control. With CMHs, you’ll ensure your plants receive these benefits.
- CMH kits produce less heat than HPS/MH grow light kits. Though HPS/MH grow lights are great for many growers’ indoor tent setups, they’re notorious for generating a lot of heat. CMH grow lights produce less heat and therefore don’t cause your grow room to become overheated. This is great for overall climate control in your grow room, and it prevents your plants from becoming burned or receiving other types of heat damage.
- A CMH bulb has a lifespan of up to 24,000 hours, or nearly 3 years. While the longevity of a grow light depends on the grower’s use, CMH bulbs or lamps are typically known to have long lifespans. This will allow you to grow using the same bulb for quite a long time.
- CMH grow lights don’t consume too much energy compared to HPS/MH kits. Compared to HPS and MH lights, ceramic metal halide grow lights consume less energy while providing high intensity coverage. Because CMHs produce large amounts of PAR light, a lower-wattage CMH can give you the same intensity of light as a higher-wattage HID light.
Whether you’re an expert grower looking for a new light or a beginner who needs high intensity, CMH grow lights are a great option. Now that you know why these lights are so efficient, you’re probably asking yourself what the best CMH grow light is? Let’s take a look at the top picks of 2020 so you can decide for yourself.
The Best CMH Grow Lights of 2020
There are a lot of grow lights out there, with plenty of CMH options for you to consider. We’ve narrowed it down to the 5 best CMH grow lights of 2020. So if you’re looking for more intensity, or you’re trying to save a few bucks, these are the best CMH grow light kits to choose from.
1. Yield Lab Professional Series 120/220v 630w Dual-Bulb CMH Open Wing Complete Grow Light Kit
The Yield Lab Professional Series 120/220v 630w Dual-Bulb CMH Complete Grow Light Kit is one of the most balanced CMH grow lights around. With its dual-bulb design, this grow light kit is able to provide a strong light for your plants. Its balanced blue and red wavelengths mimic the sun’s light and offer an extra UVB spectrum that most other MH bulbs don’t include. 
The open wing design of the reflector on this CMH grow light kit helps dissipate heat toward the top of the light rather than downward to your plants. In addition, the dimmable ballast allows you to switch between 50, 75, or 100 percent of this CMH grow light’s intensity.
If you need a powerful CMH grow light that can still keep things relatively cool, this Yield Lab kit will give you what you’re looking for.
CMH Grow Light Specs
- Wattage: 630w (315w x 2 bulbs)
- Lumen output: 36,000 lumens per bulb
- Color temperature: 3100k, 4200k CMH bulb available here
Our Price: $379.95 | Click Here to Buy This CMH Grow Light
2. Phantom CMH Reflector, Ballast, and Lamp Kit - 4200K
The Phantom CMH Reflector, Ballast, and Lamp Kit stands out because it combines simplicity and effectiveness.
The kit includes a Philips Double-Jacketed Master Color 942 CDM Elite MW 315w Ceramic Metal Halide Bulb. This CMH bulb offers a 4200k spectrum that gives your plants a nice boost during the vegging stage and necessary intensity during the flowering stage.
The CMH grow light’s reflector has vents on both sides for faster cooling compared to other grow light kits. This makes it perfect for growers operating a smaller grow room or compact grow tent. In addition, the optional CMH Reflector Cooling Kit will provide further cooling, perfect for growing in tight spaces.
As an added bonus, the ballast included in this CMH grow light kit runs at a much lower frequency than most other ballasts. As such, it won’t interfere with your home Wi-Fi signal if it’s near your router setup.
CMH Grow Light Specs
- Wattage: 315w
- Lumen output: 34,300 lumens
- Color temperature: 4200k, 3100k CMH grow light kit available here
Our Price: $447.99 | Click Here to Buy This CMH Grow Light
3. Yield Lab Professional Series 120/220v 315w All-In-One Hood CMH Complete Grow Light Kit
The 315w Yield Lab CMH bulb included with the Yield Lab Professional Series 120/220v 315w All-In-One Hood CMH Complete Grow Light Kit offers brighter intensity than a standard MH bulb. 
As such, your plants are provided with a constant stream of strong 3100k light with a hint of UVB. This UVB light helps plants in different ways — for example, UVB allows for higher resin production in plants.
The compact, all-in-one design of this CMH grow light kit combines the reflective properties of a hood reflector with the vertical light of an umbrella hood. This helps your plants receive more light out of the kit’s CMH bulb than most horizontal bulbs typically offer.
If you’re looking to grow 2 to 3 plants, this Yield Lab CMH grow light kit will give you everything you need for quality harvests.
CMH Grow Light Specs
- Wattage: 315w
- Lumen output: 36,000 lumens
- Color temperature: 3100k, 4200k CMH bulb available here
Our Price: $239.95 | Click Here to Buy This CMH Grow Light
4. Yield Lab Professional Series 120/220v 630w Dual Bulb CMH Complete Grow Light Kit
The Yield Lab Professional Series 120/220v 630w Dual Bulb CMH Complete Grow Light Kit is a powerhouse when it comes to providing light for your plants. 
Powered by an adjustable digital dimming ballast, this grow light kit includes two Yield Lab 315w 3100k CMH bulbs, giving your plants a nice spectrum of light.
One of the more compact CMH grow lights available, this kit is about 2 to 3 inches shorter than most comparable HID grow light kits. This means you’ll be able to raise and lower the fixture inside your grow tent with no hassle. This will in turn allow you to adjust the intensity of your grow lights depending on what your plants need.
If you need a lot of light in a compact grow room or grow tent, this is the optimal kit for you.
CMH Grow Light Specs
- Wattage: 630w (315w x 2 bulbs)
- Lumen output: 36,000 lumens per bulb
- Color temperature: 3100k, 4200k CMH bulb available here
Our Price: $389.95 | Click Here to Buy This CMH Grow Light
5. B.Lite 630W CMH All-in-One Fixture & Sunmaster Lamps
Though not the lowest-priced CMH grow light available, the B.Lite 630w CMH All-in-One Fixture features great intensity for your plants, which makes it worth the cost. 
The two 315w Sunmaster CMH bulbs included in this kit will ensure your plants get all the light they need throughout their entire growth cycle.
The high-efficiency ballast included with this B.Lite kit operates at a low frequency and thus offers lower harmonic distortion. That way you don’t need to worry about any interference while you're using any devices nearby.
CMH Grow Light Specs
- Wattage:630w (315w x 2 bulbs)
- Lumen output: 32,500 lumens per bulb
- Color temperature: 3850k, 3000k CMH bulb available here
Our Price: $340.00 | Click Here to Buy This CMH Grow Light
A CMH Grow Light Is a Great Choice for Your Grow Room
So there you have it! Now that you know the benefits of CMH lights, as well as the best CMH grow light kits available right now, you’re ready to make a decision. Whether you’re going for wider, more intense coverage or a smaller kit that’ll save you some money, there are multiple options for virtually every grower.
There are advantages to all grow lights. While some growers may prefer HID or LED lighting for their specific needs, a CMH grow light might be perfect for your grow room. CMHs offer large coverage at a lower wattage, a wide spectrum of light including UV light, and low power consumption.
CMH grow lights are ideal for anyone from seasoned growers with large tents to first-timers who are growing one or two plants. You really can’t go wrong with a good CMH light in your grow room.
Editor’s note: This post was originally published in October 2018 and has been updated for accuracy and comprehensiveness as of December 2020.