🧪 Our review process
Our testing team independently researches, tests, and recommends the best products to help keep your houseplants absolutely thriving. Learn more about our testing and review process here.
Thick, wet air may sound like a nightmare to us humans, but getting a humidifier for your grow tent can be a dream come true for your indoor plants. Dry air can cause all sorts of problems, from stunted growth to nutrient burn. A grow tent humidifier can increase the amount of moisture in the air and create a more hospitable environment for all to thrive.
If your grow tent is in desperate need of a little extra humidity, below are the top machines that will help get the job done.
Our top picks
When the air in your grow tent starts to feel like the Sahara Desert, the humidifiers below will be a lifesaver for your indoor plants.
1. BEST OVERALL: LEVOIT Humidifier
Product Specs
- Tank Capacity: This machine can hold 2.4 liters of water.
- Run Time: This machine can run for up to 24 hours.
- Coverage Area: This machine can cover up to 290 square feet.
With 360-rotation and an eerily quiet operation, the LEVOIT has made a lot of plants (and plant parents) very happy.
There are humidifiers that work—and humidifiers that work well. The LEVOIT is the latter. Covering up to 290 square feet and having a run time of up to 24 hours, this machine is ideal for small to medium-sized grow tents in dire need of some extra moisture.
You can adjust the 360-degree nozzle to direct the cool mist exactly where you want it to go and leave it be. The auto-shut-off feature will turn the humidifier off when the water level gets too low, so you don’t have to worry about coming home to a dried-out tank. As an added bonus, the LEVOIT also has a built-in calming night light for those who appreciate the ambiance.
The only downside to this machine is that it only uses cool mist, not warm. So, if you’re looking for a humidifier that can do double duty, the LEVOIT might not be the best option.
Pros
- Has a quiet operation
- Comes with a 360-degree nozzle
- Will automatically shut off
- Comes with a calming nightlight
- Cost is very affordable
Cons
- Only emits cool mist
- Not ideal for large tents
2. BEST BANG FOR THE BUCK: Smart Devil Small Humidifier
Product Specs
- Tank Capacity: This machine can hold 500ml of water.
- Run Time: This machine can run for up to 18 hours.
- Coverage Area: It’s not clear how much space this machine can cover, but it’s not a lot.
Low-cost doesn’t have to mean low-quality, thanks to this small but mighty humidifier.
Not every grower has the budget for a top-of-the-line humidifier, and that’s okay. The Smart Devil Small Humidifier is an excellent cost-friendly option that will still get the job done.
This machine is on the smaller side—holding only about 500 milliliters of H2O—but don’t let that fool you. It can keep your plants nice and moist for up to 18 hours, depending on which spray option you choose. Continuous mode will give you the shortest runtime, while intermittent mode will make the humidifier last the longest.
The downside is the size and capacity, of course. The Smart Devil won’t cover an entire room, but if you have a super-small grow tent or grow area, it could be perfect.
Pros
- Price is very low
- Two different mist settings
- Small and lightweight design
- Comes in multiple colors
Cons
- Small tank size and capacity
- Not ideal for large tents
- Not the longest run time
3. BEST FOR SMALL TENTS: Pure Enrichment MistAire Studio Cool Mist Humidifier
Product Specs
- Tank Capacity: This machine can hold .7 liters (34 ounces) of water.
- Run Time: This machine can run for up to 10 hours.
- Coverage Area: This machine can cover up to 175 square feet.
Maintain the perfect level of humidity for your small grow tent with this sleek and stylish humidifier.
When you’re looking for a humidifier to cover a small space, you need two things: a machine that can emit a good amount of moisture and one that doesn’t take up too much room. The Pure Enrichment MistAire hits both of those marks.
This tiny humidifier can emit up to 80ml per hour and can run for up to 10 hours on a single tank. That’s more than enough power to keep a small tent or grow area at the perfect level of humidity. Choose between the high and low mist settings to control the output, and enjoy the relaxing blue nightlight that doubles as a way to see the water level in the tank.
Since the Pure Enrichment MistAire is on the small side, it doesn’t have the same tank capacity as other options. But, it makes up for that with its low price tag and compact design.
Pros
- Price is very affordable
- Small and compact design
- Comes with Two mist settings
- Includes a built-in nightlight
- Has a quiet operation
Cons
- Has a shorter run time
- Small tank size and capacity
4. BEST FOR LARGE OPERATIONS: Aprilaire 500 Whole Home Humidifier
Product Specs
- Tank Capacity: This machine doesn’t have a tank, so you never have to worry about refilling it.
- Run Time: This machine can run 24/7.
- Coverage Area: This machine can cover up to 3,600 square feet.
You can adjust your entire home to the right humidity levels with this massive whole-house humidifier.
A big grow operation needs an equally big humidifier, and the Aprilaire 500 Whole Home Humidifier is up to the task. This behemoth can output 12 gallons of moisture per day, making it more than capable of handling a large home or grow tent.
The Aprilaire 500 is designed to be installed directly into your HVAC system, so it will work with your furnace to evenly distribute the humidity throughout your home. That means you won’t have to worry about any hot spots or dry areas, and your plants will always be in the optimal environment.
The only downside is the price tag—this humidifier isn’t cheap. But, if you need serious power, the Aprilaire 500 is the way to go.
Pros
- 12 gallons per day
- Evenly distributes humidity throughout home
- Works with your HVAC system
- Doesn’t require constant refilling
- Set it and forget it
Cons
- Priced on the higher side
- Requires an HVAC to work properly
- May require professional installation
5. BEST WITH SMART TECHNOLOGY: LEVOIT OasisMist Smart Cool and Warm Mist Humidifier
Product Specs
- Tank Capacity: This machine can hold 4.5 liters of water.
- Run Time: This machine can run for up to 45 hours.
- Coverage Area: This machine can cover up to 430 square
With customizable schedules and remote operation, this smart humidifier makes maintaining the right levels of moisture easier than ever before.
The LEVOIT OasisMist Smart Cool and Warm Mist Humidifier takes the hassle out of moisture maintenance. No more forgetting to refill the tank or check the humidity levels—this smart machine does it all for you.
Create a schedule using the free VeSync app, and the humidifier will automatically turn on and off at designated times. The app also comes with a plant care feature that tells you the exact humidity levels, temperature, sun exposure, and fertilizer schedule for each specific plant. And, if you’re not home to shut it off, the app allows you to do so remotely.
The LEVOIT OasisMist is one of the more expensive options on the list, but the features and convenience are definitely worth the splurge.
Pros
- Cool and warm mist options
- Output of 550ml per hour
- Comes with free app
- Customizable schedules and remote control
- Plant care help and identification
- Can add essential oils
Cons
- More on the expensive side
- Not ideal for large tents
Our verdict
Our top picks for the best grow tent humidifiers are the LEVOIT Humidifier and the LEVOIT OasisMist Smart Cool and Warm Mist Humidifier. Both are great tank capacity, run time, and coverage area—everything you need to keep your tent’s air healthy and humidified.
Our recommendations
| # | Preview | Product | |
|---|---|---|---|
| 1. |  |
BEST OVERALL: LEVOIT Humidifier | view on amazon |
| 2. |  |
BEST BANG FOR THE BUCK: Smart Devil Small Humidifier | view on amazon |
| 3. |  |
BEST FOR SMALL TENTS: Pure Enrichment MistAire Studio Cool Mist Humidifier | view on amazon |
| 4. |  |
BEST FOR LARGE OPERATIONS: Aprilaire 500 Whole Home Humidifier | view on amazon |
| 5. |  |
BEST WITH SMART TECHNOLOGY: LEVOIT OasisMist Smart Cool and Warm Mist Humidifier | view on amazon |
How we chose the best grow tent humidifier
Indoor gardening is all about efficiency. So we looked for humidifiers that could cover a decent amount of space and run for long periods without needing a refill. Any additional features that made maintaining moisture easier—like customizable schedules, auto-shutoff, and remote operation—made a humidifier even better in our book.
We also kept an eye on the price tag, as we know creating a grow tent setup can be costly. But, we didn’t want to sacrifice quality for the sake of a few extra bucks. The best grow tent humidifiers struck the perfect balance of features, power, and price.
Who this grow room humidifier is for
Not everyone needs a humidifier for their grow tent. Your plants may already have optimal levels of humidity, so grab a hygrometer and check your rH level before making a purchase. If the level is too low, investing in a humidifier will be beneficial for the health and growth of your plants.
What to know before you buy a humidifier for grow tent
Every humidifier will do its job: add moisture to the air. But how it does it can be the difference between thriving plants and stunted sickly ones.
Before you start your internet search for the best grow room humidifier, consider the size of your space, the type of plants you’re growing, and your climate. These factors will help you zero in on the right model that will keep your indoor jungle healthy and happy.
Most plants will prefer relative humidity (rH) between 40 and 80 percent. Be sure to measure your humidity levels before installing a humidifier in your grow tent. You can easily measure humidity levels with a hygrometer.
NOTE: A humidifier is not necessary unless your grow room is drying out and/or rH dips below the recommended 40 percent threshold.
Size
Your grow room only has so much room for your plants to, well, grow. You can’t have all of their precious real estate taken up by a gigantic humidifier. And on the flip side, you don’t want to choose a humidifier that’s too small for the job, which will lead to dry air and even drier plants.
Generally speaking, the bigger the space, the bigger the footprint. Most humidifiers will list the square footage they can cover, so have your grow room’s dimensions on hand to choose a model that can adequately handle the size.
Mist temperature
Humidifiers can produce both cool and warm mist, and what’s best for your plants depends on the climate you live in.
If you live in a hot climate with a lot of dryness, your plants will do better with a cool mist humidifier to mimic the conditions they’d experience in the wild. But if your hometown is characterized by cold conditions, then a warm mist humidifier will do a better job of keeping your plants’ roots nice and toasty.
Live somewhere that gets a little bit of everything? Opt for an ultrasonic humidifier with both cool and warm mist options.
Automatic vs. Manual
Running a humidifier doesn’t take a lot of effort, but some more advanced models can make the job even easier. Ultrasonic humidifiers can raise and lower the temperature of humidity in your room automatically, so you don’t have to constantly adjust the settings. Some also come with programmable timers that let you set it and forget it.
Lower-priced humidifiers tend to be more hands-on, requiring you to monitor the temperature and humidity levels in your room yourself. But if you don’t mind doing a little bit of legwork, these models will still get the job done.
The advantages of using a humidifier in your grow room or grow tent
Cannabis is a fickle plant. Just the slightest change in environment can result in subpar bud development or, even worse, a total crop loss.
That’s why so many indoor growers rely on humidifiers to maintain the delicate balance of moisture in the air. By keeping the humidity levels in check, humidifiers help to create the perfect conditions for growing healthy, high-quality cannabis.
There are several benefits to using a humidifier in your grow room, starting with better plant growth. When you’re plant-parenting seedlings, you need to provide them with as much as 70% humidity. Those needs change as your plants grow and develop, but they’ll almost always need more moisture than the average home can provide.
But when you commit to using a humidifier, you can create the perfect environment for your plants no matter what stage of development they’re in. That results in a lower risk of disease, pests, and mold. Not to mention, it helps your plants grow bigger, healthier, and faster.
- Consistent humidity (especially during the seedling stage) results in better yields.
- You decrease your plants’ risk of disease.
- You keep your plants protected from too much exposure to heat or cold.
Tips for using a grow humidifier
Unlike other grow tent tools like lighting, there’s not much know-how required when it comes to using a humidifier in your grow room. Most models come with simple instructions that tell you how to fill the tank and operate the controls. But there are a few things to keep in mind to get the most out of your humidifier—especially where you place it.
Cannabis plants grow best between 40 and 80 percent relative humidity (rH), which measures the amount of water in the air. If you have fresh air circulating through the grow tent, like with an inline fan, then you should be able to control humidity fairly easily. Aim for 60 percent rH, as measured by a hygrometer. NOTE: A humidifier is not necessary unless your grow room is drying out and/or rH dips below the recommended 40 percent threshold.
You want to place your humidifier as close to your plants as possible. That way, the moisture has a shorter distance to travel, and your plants will be able to absorb it more quickly. But you may have to experiment with other placement options if you’re worried about your grow tent humidity levels getting too high.
If high levels of humidity are a concern, you can opt for a combination humidifier-dehumidifier. These all-in-one machines help to take the guesswork out of maintaining the perfect environment for your plants. Just set the desired humidity level, and the machine will do the rest. NOTE: Proper ventilation should prevent excessive moisture and will be cheaper than using a dehumidifier.
No matter what type of humidifier you choose, be sure to clean it regularly. Most models come with specific instructions on how to do this, but you can usually wipe down the inside of the tank with a mild soap and water solution.
Key takeaways:
- A humidifier is not necessary unless your grow room is drying out and/or rH dips below the recommended 40 percent threshold.
- Place the humidifier close to your plants so they can absorb the moisture.
- Use a combination humidifier and dehumidifier if you’re worried about too-high humidity. Proper ventilation should prevent excessive moisture and will be cheaper than using a dehumidifier.
- Clean your machine regularly to avoid the build-up of mold and mildew.
FAQs
Unlike other kinds of grow room tools, humidifiers are (thankfully) easy to operate. But you may still have some questions about how to effectively use one to create a thriving environment for your plants. Here are the answers to some of the most frequently asked questions about grow room humidifiers.
What size humidifier do I need for a grow tent?
The size you’ll need depends on the size of your grow tent. Measure how many square feet your space is, and choose the machine that can accommodate that.
How do I bring up the humidity in my grow tent?
The most effective way to raise the humidity in your grow room is by using a humidifier.
Should I leave the humidifier on all night for plants?
No—how long you run the humidifier depends on your plants and the climate you live in. However, 4-5 hours a day is a good rule of thumb.
Shop our recommendations
- The Best Hydroponic Tower For Indoor Gardening
- 10 Best Worm Composter Bins For Easy Homemade Compost
- The Best pH Meter For Soil
- The 6 Best Dehumidifiers For Grow Tents
- The Best Complete Indoor Hydroponic Grow System
- 5 Best Grow Light Strips For Indoor Plants
- TESTED: Aerogarden vs Click and Grow Smart Garden
- Our *hands on* MARS HYDRO TSW 2000 review (with photos)
- 7 Best Hygrometers For Indoor Plants
- The Best Coco Coir For Your Plant’s Healthiest Root System Ever
Marquis *wants* to know how to keep happy and healthy plants, but had a hard time finding information that wasn't written by just another copywriter. After nearly losing one too many plants, it was time to take matters into her own hands. A team of plant scientists and nursery hands was brought together and The Indoor Nursery was born.
