It is a constant struggle for growers like us to keep the humidity down to ensure a growing plant’s survival. We must protect fattening buds from botrytis and powdery mildew. On the other hand, cuttings and seedlings require double the humidity levels of their flowering counterparts.
Plants at different stages of growth require different levels of humidity. During the first month or so, young plants would need extra 65% to 70% humidity for robust growth.
This humidity is essential to help young plants absorb water through the leaves since their roots haven’t completely developed yet.
At this point, too little humidity will spoil the growth of your young plant, which could result to lower yields in the long run.
But using a humidifier in a grow room can keep relative humidity in check. So, to help you control moisture, you must invest in the best humidifier for a grow room.
In this article, I'm going to reveal the best models on the market you can consider. Likewise, I'm going to discuss the essential factors you should be aware of before purchasing a humidifier for your grow room or grow tent, including the right size of the humidifier you actually need.
What Should The Humidity Be In A Grow Room Or Grow Tent?
Temperature and humidity in a grow room work together to keep your plants alive. Keep in mind that humidity is significant because root systems have not fully developed yet, so the leaves provide water and nutrients.
Young plants need around 65% to 70% humidity level for active growth for the first month or so.
This is equivalent to steady temperatures of 70 to 80 degrees Fahrenheit. Hence, warmer temperatures create higher relative humidity levels.
Why You Should Use A Humidifier In A Grow Room
- Help plants during photosynthesis.
- To control and increase the moisture level, ensuring clean air in a grow room.
- Get increased plant yields and size.
- Faster root development.
- Remember: too low or too high humidity can kill your plants.
- Minimizes the concentration of bacteria, dust, and other irritants.
- Growers get exposed to a grow room's dry air that can cause sinus infections, irritation, and allergy.
Now that you've understood the different aspects involved in using a humidifier in a grow room, it's time to pick the best one!
How To Choose The Right Size Humidifier For Grow Tent & Grow Room
The first step to a successful indoor gardening is analyzing the right size of a humidifier, especially its tank capacity, for your grow room.
The size of the humidifier depends on how big your grow room is and how many plants you are trying to grow.
Essentially, a small humidifier can cover up to 300 square feet while a medium humidifier can handle 350-500 square feet. Meanwhile, a large one can serve a grow room of about 550-1000 square feet. But remember, the bigger the humidifier, the more expensive it will be.
For example, if you have a 2x2 grow room that requires about five ounces of moisture a day, hOmeLabs Compact Dehumidifier is a good pick. If you have a 4x4 grow tent and you want to keep relative humidity at 40%, then you can opt for a humidifier that has a 1-gallon water tank capacity.
Things To Remember Before Buying A Humidifier For Your Grow Room
Pro tip: you can use tap water, but the filters will last longer with distilled or reverse osmosis water. Minerals from the tap water will be trapped in the filter and eventually prevent the filter from absorbing any water.
Thus, micro-elements become trapped in the humidifier and the filter must be changed.
Which Type Of Humidifier Is Best For Grow Room?
Ultrasonic humidifiers, like the Vornado Evaporative Humidifier, have the most automated features and can produce a fine mist, but automation is costly.
Go for an evaporative or cool mist humidifier if you're working on a budget.
Cool Mist Versus Warm Mist Humidifiers
Warm mist humidifiers disperse steam and include mineral filters that trap water deposits. Newsflash -- cool mist humidifiers tend to use less power than warm mist humidifiers.
Obviously, look for a humidifier that produces cool mist.
This is usually evident on a product name, mind you. Choose among evaporative, impeller, and ultrasonic models, like the Pure Enrichment Hume Ultrasonic Cool Mist Humidifier.
Who doesn't love owning a piece of equipment that can withstand the test of time? Bet on a humidifier that will require the least amount of cleaning such as ultrasonic and cold mist humidifiers since maintenance adds up to your workload and cost.
Let me stress this-- you'll end up cleaning and replacing the filter more often when you use tap water. Like I said earlier, tap water can cause mineral build-up and affect your humidifier if not cleaned.
Is Noise A Concern?
All humidifiers create noise, there's no exception. The least noisy are the ultrasonic and evaporative humidifiers. Don't worry, your growing plants are just after humidity.
It goes without saying, know the limits of your budget.
Brand To Choose
Credibility works wonders; don't you think? If you're a grower who relies on established brands, I'll introduce you to Honeywell HCM350W Germ Free Cool Mist Humidifier later.
I've already mentioned some of the best humidifiers for a grow room. But with the factors explained above, what is the most cost effective grow room humidifier?
How I wish I could give a single humidifier to consider. I kid you not, you must look into the details to snag the best deal!
Carry on, let's chat about the importance of a humidifier in a grow room and what the best ones are.
8 Best Humidifier For Grow Room Or Grow Tent – Cheap, Small, Medium, Large
Best Pick for grow room: Honeywell HCM350W Germ Free Cool Mist Humidifier
Did you know that Honeywell has been manufacturing humidifiers and air purifiers for more than 100 years?
One of those is the HCM350W Germ Free Cool Mist Humidifier that features evaporative technology that adds cool mist to dry air.
This model also allows you to choose from three fan speeds. The one-gallon tank impacts humidity in a 500 square feet grow room by extracting moisture for up to 24 hours on low speed.
It pushes air through a relatively large wick that sits in the water. The high speed setting raises humidity levels in a grow room, while the medium speed maintains relative humidity. As a result, humidity levels can be between the usual 40% to 60%.
The maintenance depends on the cleanliness of the water you use. Generally, it’s recommendable to clean the Honeywell HCM350W every 21 to 28 days.
I'll vouch for its self-regulating function, which adjusts the moisture output automatically in my grow room and gives the maximum amount of humidity possible.
Why We Like It
Evaporative Technology blows moisture off a wicking filter to evaporate the water, ensuring that the air coming out contains pure water and no trace of mineral, white dust, or other contaminants.
This grow room humidifier also has a wide tank opening for effortless refilling, replacing, and cleaning. It is larger than the other humidifiers, but it brags clean and cool mist.
Well, you won't appreciate that the Honeywell HCM350W has no auto shut-off or water refill indicator.
Best cool mist Option: Pure Enrichment Hume Ultrasonic Cool Mist Humidifier
The Pure Enrichment Hume Ultrasonic Cool Mist Humidifier can produce more than 1.5 gallons of moisture into the air in a 270 square feet grow room.
It can operate for up 12 hours on the highest setting without needing to refill the water tank.
Quick Facts: 8.3 x 6.7 x 11.8 inches, weighs 4.3 pounds, humidifier base, water tank cap, easy-clean 3.5 L water tank capacity, variable mist settings, user manual, five-year warranty, 30-day money back guarantee
Bonus Feature: Integrated Safety Mechanism, Automatic Shut-Off, and Ultra-Quiet Operation.
What I love about this model are its multiple mist options where the nozzle can be adjusted to gradually increase or decrease the amount of mist released. Its wide nozzle emits mists of up to 300 milliliters per hour.
The Pure Enrichment Hume Ultrasonic Cool Mist Humidifier is a great addition to your grow room if you're all about energy efficiency and lightweight material.
This small humidifier only consumes 25 watts of energy and has automatic safety features that turn the humidifier off when the water tank is removed or the water level is low.
So far, I've had no problems with leaking and damage to surface from the moisture. The unit's rotating mist control also allows me to conveniently adjust moisture output and direct the mist where I want it to be.
Note that its maximum operating time may depend on the room temperature, the amount of water in the tank, and the water quality.
Why We Like It
Easy to operate, ultrasonic, and doesn't use a lot of electricity. The tank has an extra-wide opening, which makes it trouble-free to remove mildew or build-up.This grow room humidifier can be easily cleaned using a small brush or even your hand. The device doesn't require a filter. The product is also made from durable plastic.
The Pure Enrichment Hume Ultrasonic Cool Mist Humidifier doesn't include an antimicrobial or silver insert to prevent the water from getting slimy. However, I've found that putting an Aquastick avoids the formation of slimy water.
Best for 2x2 Grow Area: hOmeLabs Compact Dehumidifier
The term compact itself is enough to make you add it to your cart, especially if size is a crucial factor for you.
On the flipside, the hOmeLabs Compact Dehumidifier’s ability to emit moisture is limited to up to 9 ounces of mist on a daily basis, but can only cover and purify the air in enclosed spaces like a 50 square feet grow area.
Quick Facts: 6.5 x 5.3 x 8.5 inches, weighs 2.6 pounds, 500 mL water tank capacity, made from plastic, user manual, two-year warranty, 30-day return for any reason, lifetime technical support
Bonus Feature: Low noise thermoelectric Peltier module and energy efficient 25W ETL adapter to prevent overheating.
It was also built with an auto shut off feature that cuts off the humidifier to prevent overflowing. Moreover, the hOmeLabs Compact Dehumidifier is safe from overheating since the water cannot pour out on its own.
This adorable humidifier might surprise you because despite being small, it can still serve your much needed cool mist for up to 250 milliliters per hour. It even has the capability to protect your plants from mold, mildew, and moisture rot.
Based on experience, it's advisable to clean it on a weekly basis to prolong its use.
Why We Like It
The hOmeLabs Compact Dehumidifier is designed for small spaces so you might have to buy more than one if your grow room covers more than 100 square feet.
Yet, this model is definitely perfect if you want a compact humidifier that can efficiently operate for hours and doesn't impact your electricity bills too much. It also boasts an automatic shut off system and LED indicator when the tank is full.
Unfortunately, the percentage of humidity cannot be adjusted because the only settings are on and off. This grow room humidifier doesn't come with a continuous drain outlet, but it has a small piece of waterline.
Budget Option: Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier
Despite being almost a decade-old brand, Pure Enrichment was able to create the compact Enrichment MistAire Ultrasonic Cool Mist Humidifier that has low and high speed settings to safely moisturize the air for up to 16 hours.
The unit even has an impressive 360-degree mist nozzle, which you adjust to direct the flow of mist away from areas of the grow room that don't need moisture.
The Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier also includes a speed adjuster that allows you to set how moist you want your grow room to be.Don't let the small water tank fool you because it can deliver moisture of up to 150 milliliters per hour and cover a grow room of about 300 square feet.
Another good thing about this grow tent humidifier is that it only requires one-button for four modes.
Why We Like It
The nozzle can be pointed toward different areas of your grown room. Safe because of its small size and auto shut-off function. Convenient because the whole humidifier could be easily cleaned because there are no separate filters.
Due to its compact size, the Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier must be refilled often. Also, you must separately purchase a demineralization cartridge.
Remember that it only has two settings?
Sometimes the low setting won't spray enough mist to cover your grow room while the high setting might emit too much mist around it.
Venta LW15 Airwasher 2-in-1 Humidifier and Air Purifier
Your biggest takeaway from the Venta LW15 Airwasher 2-in-1 Humidifier and Air Purifier is that it humidifies dry air, while consequently purifying the air by removing pollen, animal dander, dust, and other allergens.
It is equipped with filter pads and internal disks that trap harmful particles with water.
However, smaller particles like mold spores and pollen might not be trapped as efficiently.
Compact yet efficient, the Venta LW15 Airwasher can control the humidity of a 200 square feet grow room in just 32 watts of energy. Like most humidifiers, it's built with an auto shut-off with water refill indicator light.
In addition, Venta has been a powerhouse name for indoor air products for 35 years now, cementing their credibility in the businesses.
True to its mission, Venta designed the LW15 Airwasher on the principle of natural evaporation, which is undeniably one of the best ways to humidify a grow room.
Why We Like It
Venta is known for their long life, low maintenance, energy efficient, and high-quality products. The LW15 Airwasher is a perfect example, being armed with a humidifier and airwasher in one device.
No filter cleaning technology or replacement items needed to operate the machine.
Sad to say that this grow room humidifier does not come with a humidistat to set your preferred humidity level nor a hygrometer to inform you when the humidity levels are good enough to turn the machine off.
Best for Large Grow Room: Vornado EV100 Evaporative Whole Room Humidifier
If you're a fan of controls, minimalism, and modernity, then I'd like you to meet the Vornado EV100 Evaporative Whole Room Humidifier!
It has an air outlet grill that initiates the unit's vortex circulation. You can easily operate it using electronic push-buttons, letting you control the humidity level between 40% to 60%.
Quick Facts: 12.3 x 13 x 8 inches, weighs 5.3 pounds, 1-gallon water tank capacity, crystal-clear SimpleTank System for easy refill, five-year warranty
Bonus Feature: Vortex Action technology that ensures balanced and complete humidification.
What I appreciate the most about this is the one-gallon tank capacity that can circulate humidified air throughout a 300 square feet grow room for up to 24 hours.
It will even last longer when set on low fan speed. Vornado EV100 has three fan settings that allow you to personalize humidity: low, high, and auto.
Living up to its name, the SimpleTank system provides a crystal clear water tank, which makes it convenient for growers to determine if the tank must be cleaned or refilled.
The electronic humidistat reads humidity in the room for automatic humidity control. The wick, which filters out impurities, should be changed every one to two months.
Why We Like It
Vornado EV100 builds up natural evaporation, which eliminates white dust. The product is lightweight despite having a big water tank, allowing you to move it easily across your grow room.
This grow room humidifier is advisable if you aim for well-balanced humidification and easy maintenance.
This equipment is built to meet voltage requirements in the USA and may not function properly when operated in conjunction with external devices.
All warranties will also be voided by improper use or shipping the item outside the USA.
Best For 5x5 Grow Tent : AIRCARE Space-Saver Evaporative Humidifier
Won't you love a six-gallon water tank that can increase the humidity in your grow room for up to 70 hours without refilling?
AIRCARE Space-Saver Evaporative Humidifier lives up to its name, providing much needed humidity to dry air in a 2700 square feet grow area.
Quick Facts: 17.5 x 12.5 x 22.5 inches, weighs 14 pounds, 6-gallon water tank capacity, two-year warranty, installation manual, user guide
Bonus Feature: Super Wick Trapmax Filter Technology that absorbs minerals and unwanted impurities.
The unit's digital control panel makes it convenient to select from three fan speeds.
Growers go crazy over a machine that lets them customize the moisture level in a grow room. I present to you its three-fan speeds: nighttime, medium, and high speeds.
The droplet icon adjusts humidity from 5% to 65%, eliminating virus particles in the air. This grow tent humidifier has an auto hgallonumidistat that indicates when it's time to check the filter and refill the water tank.
I suggest placing the AIRCARE Space-Saver Evaporative Humidifier in the grow room where the moist air can be circulated to achieve effective humidification.
I've observed that the evaporative wick traps' ability to absorb and evaporate water decreases due to the accumulated minerals from the water. To solve this, I clean the humidifier once every 14 days and change the wick at least once per season.
Why We Like It
Are you hunting for a humidifier that has evaporative technology, space-saving design, refill indicator, and automatic shut-off system?
Then the AIRCARE Space-Saver Evaporative Humidifier might be your solution. The compact humidifier can run up to more than two days, giving your grow room the much needed cool mist.
The wick provides antimicrobial protection, which decreases the risk of algae and bacteria growth inside the humidifier.
Regrettably, you cannot change the moisture's direction. The grid at the top blows the air straight up. On a more serious note, AIRCARE honestly said that the model can expose users to chemicals such as benzene, which is used to create the polystyrene for wick and filter frames.
Best Commercial grade: URPOWER MH501 Humidifier
URPOWER MH501 is a must have if your location has dry winter and you want a unit that generates vapor.
It only has one power button for control, but it allows you to choose from low-medium-high humidity levels for your grow room. You can set it up between 45% to 60% to attain environmental humidity.
Quick Facts: 16.2 x 10.1 x 7.8 inches, weighs 4.55 pounds, 5L water tank capacity, Whisper-quiet Operation
Bonus Feature: A self-reading function that shuts the unit off whenever it runs out of water and a sleep mode for middle mist output.
The product's 5L water tank can disperse cool water vapor and adjustable mist for up to 14-17 hours.
Furthermore, the maximum mist volume reaches up to 350 milliliters per hour and does a good job keeping the humidity levels high.
I know you'll love this: URPOWER MH501 is condensation-free! You won't have to worry about this grow room humidifier soaking its place with liquid.
Based on trial and error, this device likes being cleaned on a weekly basis to prevent the formation of mold.
Why We Like It
The URPOWER MH501 Humidifier can last up to two nights on low setting. Aside from its portability, it has an automatic shut-off function that prevents the unit from overheating.
The humidifier also uses a plastic filter disk to clean the air.
Alas, it has a narrow-necked nozzle, making it hard to refill. The running time is also low compared to others.
Although the water filters clean the water inside the tank, the machine doesn't deal with spores, mold, pet dander, and pollen.
URPOWER MH501 Humidifier's reservoir and flask are made from polymer, which means possible leakages.
Growing plants indoors also mean investing in a grow room and a humidifier. It's undeniable that an enclosed environment protects growing plants from direct sunlight and outside forces. Yet, it's not without setbacks, and this is where a humidifier comes into the picture.
The humidifier will assist you in controlling the temperature and moisture output in a grow room, ensuring the survival of your growing plants.
I can't make the decision for you, but I can help you pick the best grow room humidifier. Go for the humidifier that is easy to operate, can reliably spread mist in your grown room or grow tent, and can operate for long hours.Veer to the side of buying one that will perform best in the conditions of your grow room. Finally, I know you've been waiting for this -- pick the humidifier for grow tent that is the right size for your desired relative humidity, doesn't require too much cleaning, and won't make you feel guilty spending cash.
Lindsey Hyland grew up in Arizona where she attended University of Arizona’s Controlled Environment Agriculture. She has supplemented her formal education by working on various organic farms, including spending a semester abroad in India.
Growing and/or raising just about anything gets her excited. She is especially passionate about environmental justice and low-tech, sustainable ways to better run small-scale farms and homesteads. Lindsey started Urban Organic Yield to discuss gardening tips and tactics.