Best Humidifier for Grow Tent

Last updated on Oct 15, 2021 Humidifiers
Note: This post may contain affiliate links. As an Amazon Associate, we only earn from qualifying purchases!

In grow tents, humidity plays a significant role in plant growth. But, you should note that not all plants thrive under similar humidity levels. For instance, tropical plants grow well under high humidity levels (60-90%), while desert plants such as succulents tolerate less humidity of about 20-40%. So, depending on the type of plant in your grow tent, humidity fluctuation may challenge your efforts. If you already have a grow tent or are planning to own one, you might be wondering the best ways to maintain favorable humidity levels. There are a few ways to do so, but a humidifier is the most effective way. In this article, we intend to help you choose the best humidifier for grow tent. We have discussed some of the best humidifiers and the basic features that make them suitable for grow tents. 

Summary of our 5 best humidifiers for grow tent

HumidifierVornado UH100 Ultrasonic Cool Mist HumidifierElechomes US5001 Cool Mist HumidifierDreamegg 4.5 L Cool Mist HumidifierPure Guardian H965AR Cool Mist HumidifierTekjoy Premium Air Humidifier
Area coverage600 ft2322 ft2485 ft2320 ft2-
Tank size (gallon)
Run time24 hours60 hours30 hours70 hours24 hours
Auto shut-offYesYesYesYesYes
Humidity settings33333

Can you put a humidifier in a grow tent?

Yes, you can use a humidifier in a grow tent. The humidifier provides and maintains the required relative humidity levels in your grow tent. However, you need to consistently monitor the humidity levels to avoid releasing excess moisture in your grow tent. Excessive humidity may be harmful to some plants. This is because in high humidity there is less transpiration, which affects the plants’ ability to absorb new nutrients. As water evaporates through the leaves, the plant draws more water from the stem. This process makes the roots take up more water and nutrients from the soil. So, as you use the humidifier, watch out for mist output. This will help you ensure all plants in the grow tent receive the required amount of moisture. 

Benefits of a grow tent humidifier

A humidifier helps regulate the moisture in the grow tent according to the plants’ preferences. As seedlings, some plants like marijuana grow well under constant moisture. However, as they grow, the levels of humidity required changes. Therefore, a humidifier allows you to change moisture output in your tent as your plants grow.

When the air in the house is dry, a humidifier can increase the humidity levels in the grow tent to keep tropical plants green, succulent and in good health. A humidifier works by maintaining stable air humidity that favors plant growth. 

How to increase humidity in grow tent?

  • Use wet towels and sponges. This is a cheap way to increase humidity in the grow tent. Put the wet towel near the ventilation of the tent. Or, you could place the wet sponges near the plants. With time, the water will evaporate thus adding moisture to the air.
  • Use a fan. Free airflow is vital for plant growth. In this regard, you can put a fan in your grow tent to increase humidity. A low fan speed ensures steady air circulation. This helps increase the humidity in the grow tent.  However, you need to set the fan speed at low or moderate speed. A high fan speed can affect the growth of your plants and may even dry them out.
  • Use propagators. This is a covered heated container filled with compost. These propagators help maintain high levels of humidity in your grow tent.
  • Use a humidifier. This is the most effective way of increasing humidity in your grow tent. It can also help you maintain a suitable humidity range that can favor your plant growth.

Challenges of low humidity in a grow tent

As plants grow, they acquire carbon dioxide from the air. In this process, the plants open the stomata to absorb carbon dioxide. As the stomata open, the plant loses water to the atmosphere. This process makes the plant collect more water from the soil medium, which is loaded with nutrients. When the humidity is low, the plants will start absorbing water from the soil at a high rate. This means the rate of water absorption is higher than the loss through stomata openings. This will result in plants closing the stomata. Consequently, this will slow down the process of photosynthesis due to limited absorption of carbon dioxide thus compromising the yields.

More so, low humidity could also make the plant wilt and die. This is because the plants’ shielding mechanisms cannot bear the dry air for long.

How to pick a humidifier for grow tent?

  • Humidity settings. You need to look out for the humidity setting on the humidifier. This regulates the moisture output. The more settings the unit has, the easier it is to maintain the humidity level in your grow tent. In general, a humidifier with 3 settings is good for any grow tent.
  • Tank capacity. When choosing the right humidifier for your grow tent, check the tank capacity. If the tank is small, you will have to refill every 12-16 hours. However, if you choose a device with a large water tank, the refilling frequency would be less.
  • Area coverage. The area coverage can be termed as the size of the tent you want the humidifier to cover. However, this should depend on how big the grow tent is and the number of plants inside. A humidifier with a small coverage can cover up to 300 square feet and a medium-sized humidifier can cover 350-500 square feet. For large capacity humidifiers, they can cover rooms of about 550-1000 square feet. So, depending on the size of your grow tent, choose a humidifier that can maintain the required humidity effectively within the grow tent.
  • Easy to clean. The tank should be wide enough to ease cleaning. The water tank can turn out to be a breeding ground for molds. These may be released into the air, especially when using cool-mist humidifiers. These can cause leaf spots, wilts and root rots when they come into contact with the plants. Therefore, the water tank should be easy to clean to minimize the chances of introducing the above contaminants into the air. 

5 best humidifiers for grow tent

1. Vornado UH100 Ultrasonic Cool Mist Humidifier

Vornado UH100 Ultrasonic Cool Mist Humidifier
Vornado UH100

First, on our list of best humidifier for grow tent, is the Vornado UH100 Humidifier. The humidifier can output mist in rooms of up to 600 square feet. UH100 also comes with a 1-gallon water tank. This allows the humidifier to work for up to 24 hours on a low setting. The humidifier allows you to select between the 3 fan settings (low, high, and auto). Low and high settings maintain 40-60% relative humidity. The auto option will provide continuous humidity output.

The humidifier features a built-in humidistat. This allows you to set your preferred level of humidity and the humidifier will maintain it.  

The UH100 carries an easy-to-clean water tank. The 1-gallon water tank can easily be carried, filled, and installed.

You do not need to worry when you are away, the humidifier has an auto shut-off feature. This shuts off the humidifier when the water in the tank is low.

Why Vornado UH100 Cool Mist Humidifier is good for a grow tent

  • Humidistat. The humidifier carries a built-in humidistat. You can preset the ideal humidity levels you would want in the grow tent, and the unit will maintain it. When the humidity in the grow tent reaches the preset level, the humidifier will automatically turn itself off. If the humidity levels drop, the unit will automatically detect this drop and turn itself on to maintain the set levels. This prevents outputting excess moisture or letting the humidity levels drop within the grow tent.
  • Tank capacity. This humidifier carries a 1-gallon water tank. This can ensure the humidifier works for up to 24 hours. Moreover, it enables the humidifier to output 2-gallons of mist every 24 hours. This means the plants in your grow tent will have moisture in the air for a long time with just one fill up.
  • Area coverage. Vornado UH100 Ultrasonic Cool Mist Humidifier can cover grow tents of up to 600 square feet. This can sufficiently humidify large grow tents of about 8x8.


  • Easy to clean
  • Built-in humidistat
  • Quiet operations on low and auto setting
  • Can be refilled without removing the lid


  • Louder on high fan speed

2. Elechomes US5001 Cool Mist Humidifier

Elechomes US5001 Cool Mist Humidifier
Elechomes US5001

Elechomes US5001 is another good option for grow tents and is the next entrant to this list of best humidifier for grow tent. This humidifier also doubles as an oil diffuser. So, you can use it in your bedroom. Elechomes US5001 humidifier holds a 5-liter water tank. This allows it to operate for up to 60 hours on low settings. You can adjust the mist output using the control knob. On maximum setting, this unit can put out 300ml of mist per hour.

The humidifier is easy to clean and refill with water. You can add water without having to remove the lid. When the tank is empty, the humidifier will automatically shut off. You can also program the humidifier with a 12-hour timer. It generates low noise levels of less than 25 dB which means you don't have to worry about any kind of noise pollution.

The humidifier features a 3600 rotating nozzle. This means you can direct the mist output to any position of your choice. Elechomes US5001 humidifier can operate in an indoor area of up to 322 square feet.

Why Elechomes US5001 cool mist humidifier is good for a grow tent

  • Tank capacity. Elechomes US5001 has a 5-liter (1.3 gallons) tank capacity. This enables the humidifier to generate mist for up to 60 working hours. In this case, plants in the grow tent will have sufficient moisture to support their growth.
  • Timer. You can schedule your humidifier with a 12-hour timer. For those with fluctuating humidity in the room, this can be a good acquisition. If the air is dry during the night, you can time your humidifier to operate until early morning. This will help not to generate excess moisture in the tent that can lead to the growth of molds and bacteria which can affect plant growth.
  • Area coverage. The humidifier has the capacity to humidify a room size of up to 322 square feet. This is good for medium size grow tents such as 5x5. In a grow tent of this size, the humidifier provides enough moisture to enable the plants to complete the process of photosynthesis and evapotranspiration.


  • Timer
  • Easy to clean and fill
  • Long run time
  • Ultra-quiet


  • No humidistat
  • No filters

3. Dreamegg 4.5 L Large Room Cool Mist Humidifier

Dreamegg 4.5 L Large Room Cool Mist Humidifier
Dreamegg Humidifier

For those with large grow tents, Dreamegg 4.5L cool mist humidifier can be a good addition to your grow tent. The unit is equipped with a smart auto-off timer. You can schedule your humidifier for 2, 4, and 8 hours depending on your choice. Furthermore, you can control the mist output in your grow tent using the humidifier’s 3 adjustable mist levels (low, medium, and high). You can set it to any level depending on the grow tent humidity levels and how quickly you want the humidity stabilized.

Dreamegg has a sleep mode feature. When turned on, the humidifier will turn off all lights including indicator lights. So, if your tent is in the bedroom, your sleep will not be interrupted.

The humidifier holds a 1.2-gallon (4.5 liters) water tank. This enables the unit to function for up to 30 hours on a low setting. Apart from humidifying, Dreamegg operates silently. Generally, it produces less than 32 dB noise levels.

The humidifier can cover medium-sized grow tents because it can humidify 485 square feet of space.

Why Dreamegg Cool Mist Humidifier is good for a grow tent

  • Tank capacity. Dreamegg carries a water tank of 1.2 gallons. This can sustain the humidifier’s operation for up to 35 hours on low settings. In this regard, your grow tent will not experience dry air as it is assured of long time humidification. Ultimately, the crops will not get wilted or grow slowly.
  • 3-level mist settings. These mist settings give you control of mist output in the grow tent. When the humidity is low, the highest setting can swiftly generate moisture until it restores the required humidity. Then the lower mist settings will ensure the moisture levels do not drop. So, plants that require high humidity will thrive with this type of humidifier.
  • Area coverage. This humidifier can cover a grow tent of up to 485 square feet. Certainly, this ensures the plants in the grow tent of this size get enough moisture to sustain their growth.


  • Timer
  • Sleep mode
  • Whisper quiet
  • Easy to clean
  • Portable


  • You need to flip it to refill. This can make the place messy due to water splashes

4. Pure Guardian H965AR Cool Mist Humidifier

Pure Guardian H965AR Ultrasonic Cool Mist Humidifier
Pure Guardian H965AR

This humidifier can help you maintain appropriate humidity levels in your grow tent. It is a cool-mist humidifier that guards your plants against problems caused by dry air. Pure Guardian H965AR can operate up to 70 hours on a low setting. This can be attributed to the large capacity water tank of 1 gallon. The run time depends on the speed setting as well as atmospheric conditions. The humidifier can cover up to 320 square feet.

The tank is protected by silver clean. This fights against the growth of microorganisms such as mold within the water tank surface.  Additionally, the humidifier features a low water indicator light. This alerts you when there is a need to refill the water tank.

Pure Guardian H965AR Ultrasonic Cool Mist Humidifier gives you the freedom to control the mist output with the 3-speed control. The unit comes with a 3600 nozzle that allows it to mist in all directions of the tent. Since the humidifier uses ultrasonic technology, it is ultra-quiet.

Why the Pure Guardian H965AR Humidifier is good for a grow tent

  • 3-speed humidity setting. The humidifier allows you to control the mist output in the tent. When there is extremely low humidity in the grow tent, you can swiftly alter this condition. On maximum speed setting, the humidifier generates a lot of moisture in a short time. This helps the plants not to wilt. However, when the humidity reaches the required level, you can maintain it using a low or medium setting. So, the transpiration process will not be interrupted, thus generating better yields.
  • Tank size. Pure Guardian has a 1-gallon water tank. This allows the humidifier to generate mist in your tent for up to 70 hours with just one fill up. However, the run time may be shorter when operating on medium or high settings. Generally, your plants will not have to endure dry air spells because of the abrupt shutdown when the tank gets empty. Even if you are not around, the humidifier will maintain the humidity levels for an extended time in the grow tent.
  • Area coverage. Pure Guardian can humidify indoor spaces of up to 320 square feet in size. This is suitable for small grow tents of 2x2, 3x3, and 3x5. This means the humidifier can fully generate sufficient moisture for all plants in these grow tents.


  • Good run time
  • Refill indicator
  • Operates quietly
  • Auto shut-off
  • Silver clean tank


  • No humidity sensor
  • Due to its slim design, it is difficult to clean

5. Tekjoy Premium Ultrasonic Air Humidifier

Tekjoy Premium Ultrasonic Air Humidifier
Tekjoy Humidifier

Another good grow tent humidifier is the Tekjoy premium ultrasonic air humidifier. This humidifier can relieve your plants of dry air. The unit comes with a 0.66 gallon tank (2.5 liters). At full capacity, this tank can support the humidifier’s operations for up to 24 hours. The tank is equipped with handles, which makes it easy to carry and refill.

When the water levels are low, the humidifier will automatically shut off to prevent possible damages. It also uses ultrasonic technology, which makes it whisper quiet. It generates less than 32 dB noise levels. The unit is good for small areas and this makes it suitable for most small indoor grow tents. You can schedule the humidifier using the 3 timer settings (4, 8, and 12 hours).

Tekjoy humidifier allows you to adjust the mist output and lights. You can use the touch control panel to select among the 3 mist settings. Similarly, you can choose among the 9 night light options to make your grow tent look beautiful. For easy cleaning, the device comes with a tank brush and 2 disk cleaning brushes.

Why Tekjoy Premium Ultrasonic Air Humidifier is good for a grow tent

  • Easy cleaning. The water tank has handles for easy lifting. In addition, it comes with disk cleaning brushes and 1 tank brush. These help ensure the tank is effectively cleaned. This prevents the growth of microorganisms in the tank. Therefore, no microorganisms will be released into the air to affect plant growth.
  • 3-mist settings. The humidifier is equipped with 3 mist output settings. These allow regulation of the amount of moisture released into the air.  On maximum setting, the humidifier can output 280ml/h. This shows how fast your plants can be supplied with moisture when there is low humidity.
  • Tank capacity. With the 2.5-liter water tank, you can be assured of 24 hours of operation on a low setting. This means the humidity in your grow tent will not drop due to shut-off caused by an empty water tank.


  • Operates quietly 
  • 3600 nozzle
  • Auto shutoff
  • Easy to clean
  • Timer


  • No humidity sensors

In summary, humidifiers are very important for grow tents.  You only need to make the right choice to have the best results. This article gives you information that can guide you in choosing the best humidifier for grow tents. 

Featured Posts

Related Posts