How To Increase/Lower Humidity In A Grow Tent : The Complete Guide

If you choose indoor gardening to grow plants, a few important factors you need to take into consideration. Humidity is one of them. In this article, we would love to tell you about how to increase humidity in a grow tent.

Apparently, grow tents provide potential opportunities to grow plants even in any weather condition. Yet, most of the indoor growers focus on other growth factors such as pH, system cleaning, pesticide management, moisture etc.

What is humidity?

What is-humidity

Eventually, many of them forget about humidity. This article aims at improving ideas about its role in getting healthy plants. Also, we will show you the ways to follow increasing the humidity level. 


What is humidity?

If you are serious about indoor gardening, it requires for gathering knowledge about the definition of humidity. In fact, the air holds a certain amount of water vapor. It is measured in RH (Relative Humidity) unit. Again, a hygrometer is widely used to measure it.

**Reasons behind not supporting low humidity for the plants:

Reason 1: low humidity

Poor growth

Lowering humidity in the grow tent leads the plants to poor growth. However, low moisture happens in getting the plants into exertion of pressure. As a result, the plants can’t grow and ends up resulting in death.

Reason 2: low humidity

Insects attack

Moreover, lower humidity level makes the leaves of plants to get dried soon. Number of insects as like as mites, molds etc. would make the best advantage of this condition and attack the plants.

Reason 3: low humidity

Excessive absorption on the roots

If enough humidity is missing, the surface mostly creates absorption on the roots. Consequently, the leaves will get desiccated for want of enough nutrition.

How to raise the humidity in a grow tent

To increase humidity in grows tent, Ideal humidity level is important for your pants to grow peacefully without any hassle. A study shows that about 60% relative humidity needs to be gathered for suitable growth of the plants.

But is that too easy when you just begin your journey with indoor growing?
We will ultimately show you the ways to increase humidity with this article. The ways of how to increase humidity will make you learn it. The following list will be helpful to gather knowledge about it. 

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1. Lower the surroundings temperature

Apparently, warm air is not so dense enough compared to cool air, right? When you discover the rising temperature inside the grow tent, definitely the air is likely to lose the capacity to retain water. That ultimately directs to the lack of humidity.

The temperature inside the grow tent


Lower temperature means that the air is moist relevantly. In that case, air holds a significant amount of vapor. Raising humidity in the grow room will start when you ensure reducing the related temperature.

By lowering the temperature, you help the plants to flourish inside the tent with healthy growth. Another effective way to follow is to lower the intensity of UV light. This relevantly decreases the hot temperature.

Nevertheless, teenage plants won’t require much intensity of light. So, never get worried about it at all.

A swamp cooler is another helpful way to help in cooling the air. This device plays a vital role in increasing humidity when the temperature is on the rise. 

2. Using a humidifier

If you want your plants to get ideal condition for growth, it requires optimum humidity for grow tent. Use a humidifier in it. Are you getting worried about the money cost? You can get it at a very reasonable price from any popular online marketplace.

The temperature inside the grow tent

The temperature inside the grow tent

In fact how humidifier works in increasing the humidity? It generates a cold mist that is conducive to the growth of the plants. Generally, you will find a humidifier engrossed with water vapor. When needed, the vapor emits from the base and makes the surrounding filled with moisture.

Hence, make sure the humidifier in grows tent needs not to be too much action in releasing vapor. Otherwise, it draws extra problem by creating an uncontrolled situation inside the grow tent. Excessive humidity is not good at all for the plants to grow on a regular basis.

Use a dehumidifier if the situation goes out of your hand. Above all, you must keep the humidity level in an ideal state for any best grow tents. For example, humidifiers for 4×4 grow tent needs enlarged space for holding more water.

When you decide to buy a humidifier, the best humidifier for grow tent has a large tank with a larger amount of water capacity. The humidifier which is not raising humidity should be replaced as soon as possible. 

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3. Allow water sources

This is an effective way to raise humidity. When you increase the number of water resources inside the grow tent, it definitely gets you gain more advantage in reaching your target.
Place a water tray or sponges in places wherever possible. Put it beside the passive air holes.

Allow water sources

Allow water sources

Moreover, putting damp sponges is another tricky way to follow. While the temperature rises, it evaporates. That’s how the moisture is going to raise the humidity. The heat generates from the ultimate air-conditioning mechanism will convert in to evaporate water.

Be sure about using fresh and clean water. Otherwise, harmful bacteria might develop and leaves bad effects on the plants. 

4. Fan setting

To raise humidity, you need to focus on fan setting well. Apparently, it helps in managing the adequate humidity inside the grow tent. The circulated air is equally distributed for the welfare of the plants.

Fan setting

Fan setting

Moreover, you need to ensure the perfection of air circulation. Another benefit from it is to the prevention of harmful bacteria or mites that is ultimately a big threat to the plant's healthy growth.

Make sure the fans are circulating air in moderate speed. This is helpful in processing air circulation smoothly. In addition, the cool air thrives to retain the moisture well.

Remember that the high speed of the fan is not too good for the plants. Ultimately it results in making the air dry soon. Apart from it, higher speed leads the plants in dehydration issues.

The process makes the air cool and regulates the entire indoor gardening retain adequate moisture.

So, ensure a minimum of 60% humidity over the plants with moderate speed that is optimum for increasing humidity. If the grow tent goes too 

5. Using mature plants inside the grow tent

If you are looking for getting another tricky way for increasing humidity in a grow tent, this one is usually helpful for you. Remember, larger plants can widely contribute to increasing humidity well.

Now you can ask me how?

The process is very simple. Bigger plants go with the respiration process. The wider leaves of them release their last product along with more water vapor. Eventually, the younger plants can retain the vapor and can grow well with the moderate humidity.

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Mature plants significantly elaborate on the improved root system. Losing water through the bigger stomata will raise the relevant moisture inside the tent.

Remember not to make a gathering of too many larger plants. This can seriously hamper the younger plants from getting enough nutrition. 

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How to lower humidity in the grow tent

Raising too much humidity never goes well for the plants. If it happens by any chances, some measures you can take by knowing how to control humidity in a grow tent.

1. Using a dehumidifier

A dehumidifier widely includes the values in lowering the raised humidity well. Drain the excessive moisture inside the tent with it.

2. Stop overwatering the plants

If you overwater the plants, it will significantly go with extreme humidity level. Moreover, we should ensure the recommended humid level for the regular growth of plants.

3. Add more ventilation

If the humidity reaches over the recommended level, try to minimize it by adding more ventilation. Add a number of fans inside the grow tent and takes it to the correct level.

Why extreme humidity is not good for plants health

We have mentioned before that low or high humidity is not going to be so suitable for the healthy growth of plants. Extreme Humidity would create more hampers in your indoor gardening.

  • 1
    It contributes to making an ideal environment for the microorganisms like mold or mites.
  • 2
    Hampers in offering efficient transpiration of the plants.
  • 3
    Extreme humidity plays a vital role to generate the growth of bacteria highly.
  • 4
    It weakens the root to absorb adequate water from the soil.
  • 5
    Photosynthesis process highly gets clogged for it.


For any growers, it is so important to keep raising the humidity to control the plants well. Now you have come to know about how to increase humidity in a grow tent with this article.

Thankfully, it includes more other information to enrich your knowledge.

I hope that you will be successful in indoor gardening even if you are a newbie. From now on, stop watching any nightmare about your loving plant's healthy growth. Hope all should come in a well set up. 

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