How to Raise Humidity in Grow Tent: 8 Easy Ways

Maintaining an optimum moisture level within indoor your grow tent is one of the most important factors for healthy plant growth. Adequate humidity ensures that your plants grow strong and big, providing you with plentiful harvest and plant products in the long run.

If you are looking for some easy ways on how to raise humidity in grow tent, we have come up with some viable solutions to your problem.

What happens if humidity is too low in grow room or grow tent?

  • Plants lose a lot of water through the pores (stomata) on their leaves, and this moisture is not always replaced through the water taken in roots absorption. Thus, low humidity does not allow the plants to compensate for that water loss by absorption of droplets from the surrounding.
  • High level of humidity is essential during initial growth phases of plants e.g., seedings. So, low humidity leads to unhealthy seedlings with stagnant growth.
  • Plants may lose too much water in low humidity, leading to dried and curled up leaves.
  • Insects, mites and molds are most likely to attack your crops in low humidity
  • Poor growth due to low moisture that may lead to the death of your plants.

Thus, you do not want your plants to meet their demise due to insufficient levels of humidity. Keep reading further as we discuss 8 easy ways to increase the moisture within your grow tent to ensure happy and healthy plants!

How to Raise Humidity in Grow Tent


Placing a humidifier into your grow tent is the easiest way to increase humidity, and it will also be a very convenient addition that will serve your plants for a very long time.

Pick the right humidifier depending on the size and type of your plants, and you will be able to adjust the moisture level in variable levels.

If you are confused about which humidifier to get, we also have an article reviewing the best humidifiers for grow tent to find an option that will best serve your needs.

Lower your fan settings 

While having sufficient ventilation is crucial to keep away unwanted odors and gasses from building up within your grow tent, if the fan speed is too high, it may remove essential humidity from the surroundings.

Thus, we suggest that in order to avoid the atmosphere within from drying up, you can lower the fan settings to find a balance between your required ventilation as well as moisture.

Decrease temperature 

If the temperature within your grow tent is too high, air will rise towards the tent’s ceiling and remove moisture away from your plants.

To avoid this, you can reduce the temperature on the heater (if you are using one), or you can also place an air-conditioner within your grow tent to avoid unwanted temperature rise.

Place a combination of small and large plants

Larger plants have leaves with bigger size and more surface area, and thus they release a lot of moisture in the surrounding through transpiration. As this moisture stays constricted within the grow tent and increases the level of water vapor within the tent, eventually the humidity level will increase.

This helps maintain sufficient moisture within your grow tent and allows healthy growth of the small plants.

Keep water sources within your grow tent 

When wondering how to increase humidity in grow tent, placing water sources in trays or appropriate containers is one of the cheapest solutions for improving the relative humidity for your plants.

As the heat of the lighting system or the heater will slowly evaporate the water from the containers, the moisture level within your grow tent will rise automatically.

Cover your plants 

During the germination process, the seedlings require high levels of humidity of about 80-90% to ensure effective growth. You can cover your small seedlings with plastic trays or plastic wraps that will create a microclimate within, and keep the moisture and humidity trapped within the tray or wrap, ensuring high moisture.

For large plants, you can opt for buying Victorian Bell Cloches with which you can cover the plants and reduce the level of humidity loss.

Ensure that your grow tent is intact and sealed 

Poorly manufactured grow tents often have rips along the seams of the zipper or have tears and splits on the fabric of the grow tent. Moreover, damages may also occur during the use of the grow tent over the years. These gaps can cause moisture to escape from within, lowering humidity.

Carefully inspect your grow tent for any such gaps or rips, and seal them up through sewing or by using duct tape. Make sure that any unused ports or vents are also correctly sealed up to maintain an intact grow tent.

Place your seedlings within propagators 

If you are willing to spare a few dollars to ensure that your seedlings are growing healthy and strong, putting them in propagators will provide them with sufficient humidity and provide you with a quick and high-quality harvest.

Propagators can retain high levels of humidity within, allowing the moisture to build up as required.


We hope that one of these ideas will surely assist you when you are looking for ways on how to raise humidity in grow tent.

For any indoor gardeners and growers, it is important that you provide proper care to your plants to make sure that your plants are growing super healthy and strong, and your efforts are not going down the drain.

Understanding important environmental parameters such as temperature and humidity and the adequate levels required for them are among the most essential parts of being a successful gardener.

So, don’t let your plants suffer due to low moisture, and apply one of these methods to keep your plants happy and healthy.


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