How to Lower Humidity in Grow Tent without Dehumidifier

Controlling the humidity in your grow tent is essential for healthy plants. High humidity can cause various plant diseases, while low humidity can lead to wilting and stunted growth. It's important to take steps to maintain the right humidity level in your grow tent, but what happens if you don't have a dehumidifier?

In this article, we'll explore methods of controlling humidity without a dehumidifier.

The Impact of High Humidity on Your Plants

High humidity levels in your grow tent can have a significant impact on your plants, leading to mold growth, pest infestations, and stunted growth. If you want to ensure the health of your plants and improve your yields, it's crucial to control the humidity levels in your grow tent.

how to lower humidity in grow tent without dehumidifier

Lowering humidity levels in your grow tent is crucial to your plant's health and productivity. High humidity levels can create an environment that promotes fungal and bacterial growth, leading to diseases that can damage or even kill your plants.

Moreover, high humidity levels can affect your plants' ability to absorb nutrients and water from the soil, leading to stunted growth and lower yields.

Without a dehumidifier, there are many cheap ways to lower humidity levels in a grow tent. You can use silica gel packets in the grow tent, replace the air filters frequently, use a fan to increase air circulation, and set up a drip system to water your plants.

Also, if you want to lower humidity levels in your grow tent when lights are off, you can open the tent's vents or use a dehumidifying salt solution.

Remember to monitor your humidity levels regularly to make sure they don't drop too low. Aim for 40-60% relative humidity for most stages of plant growth.

Strategies for Lowering Humidity in Your Grow Tent Without a Dehumidifier

In this section, we'll discuss strategies that you can use to reduce the humidity levels in your grow tent without needing to purchase a costly dehumidifier. We'll look at how to lower humidity in your grow tent at night, as well as cheap and easy ways to dehumidify your grow room.

So let's get started!

Increase Ventilation to Improve Airflow

If you want to lower humidity in your grow tent without a dehumidifier, one of the best solutions is to increase ventilation, which helps to improve airflow and brings in fresh air while removing the humid air.

increase grow tent ventilation

Here's how to do it:

  • Put a fan outside of your tent: Place a fan outside of your grow tent, facing towards the intake flaps to pull in fresh air and improve airflow inside the tent.
  • Use oscillating fans: By using oscillating fans inside your grow tent, you can improve the air circulation and maintain optimal temperature and humidity levels. Just set up one fan to blow air into your grow tent, and another to pull air out of it (place the second fan near the top of your grow tent, ideally as close to your grow light as possible, then turn both fans on).
  • Open the tent at night: If you're worried about humidity levels spiking during the night, opening the grow tent flaps slightly can help bring in cool and dry air, which can lower humidity levels.

Proper ventilation and airflow are key to managing humidity in your grow tent, so make sure to use these strategies to create the perfect environment for your plants to thrive.

Use Silica Gel or Desiccant Packs to Absorb Moisture

We can't deny that using silica gel or desiccant packs is always a cheap and effective solution for lowering humidity levels in your grow tent or room.

Here are the four steps to do it:

  1. 1
    Purchase silica gel or desiccant packs online or at a local store.
  2. 2
    Place the silica gel or desiccant packs inside a mesh bag or a small container with holes punched in the lid.
  3. 3
    Hang the mesh bag or place the container inside your grow tent, preferably near the humid areas or around your plants.
  4. 4
    Replace the silica gel or desiccant packs as needed, typically every month or so.

Using silica gel or desiccant packs can help reduce humidity levels in your grow tent without incurring expensive costs. Try it out today and see the difference for yourself.

Pros and Cons of Using Silica Gel or Desiccant Packs

Silica gel or desiccant packs are a popular choice for dehumidifying grow tents, but they also have their pros and cons.

On the pros side, silica gel packs are efficient at absorbing moisture and are relatively inexpensive compared to electric dehumidifiers. They are also reusable and eco-friendly.

On the cons side, silica gel packs have a limited capacity for absorbing moisture, so they need to be replaced regularly. They also need to be evenly distributed throughout the grow tent to be effective.

If you decide to use silica gel or desiccant packs, make sure to follow the below instructions carefully and monitor the humidity levels regularly to prevent over-drying your plants.

  • Determine how many silica gel or desiccant packs you'll need based on the size of your grow tent and the level of humidity.
  • Hang the packs inside the tent, near the plants but not touching them.
  • Monitor the humidity levels using a hygrometer and replace the packs as needed.

Incorporate Natural Dehumidifying Agents

Incorporating natural dehumidifying agents can help lower the humidity in your grow tent and improve the health of your plants.

With these natural dehumidifying agents, you can maintain ideal humidity levels in your grow tent without breaking the bank on a dehumidifier.

Let's check them out:

  • Use silica gel packets - these can absorb moisture and help maintain ideal humidity levels in small to medium-sized grow tents.
  • Place a bowl or bag of uncooked rice in your tent - rice is a natural dehumidifier and can help regulate moisture levels.
  • Add some charcoal briquettes - charcoal can absorb moisture from the air and prevent fungal growth.
  • Use baking soda - fill several bowls with baking soda and place them around your grow tent in an even distribution. Checking the bowls regularly is important as the baking soda will absorb moisture from the air and will need to be replaced once it becomes saturated.
  • Use a bucket of calcium chloride - fill a small bucket half full with calcium chloride pellets and punch some holes in the lid of the bucket. Place the bucket inside your grow tent, on top of a towel or mat to protect your floors. The calcium chloride will absorb excess moisture from the air, thereby lowering the humidity in your grow tent and creating an ideal environment for your plants.

Adjust Your Watering Practices

If there is excess humidity in your grow tent, you should cut back on the amount of water you give your plants. You don't want to over-water your plants, especially when growing cannabis in a soilless medium like coco coir.

water plants less frequently but deeply

Your plants need just the right amount of water to thrive, and overwatering can lead to high humidity levels in your grow tent.

Make sure to check the moisture level of the soil before watering, and only water when the top inch of soil is dry. You can also use a moisture meter to measure the soil's moisture level accurately.

  • Water your plants less frequently but more deeply. Over-watering can trap moisture in the soil and increase humidity levels.
  • Make sure your grow tent has proper ventilation. Good air circulation can help prevent stagnant air and excess moisture buildup.
  • Avoid watering your plants during the night or when the lights are off. This can create a humid environment that promotes mold and mildew growth.
  • Water your plants in the morning or early afternoon, before the hottest part of the day. Provide proper ventilation in your grow tent to allow the excess moisture to escape.

By implementing these changes to your watering routine, you can effectively lower the humidity in your grow tent. This strategy works best if you have plants that require frequent watering, such as herbs, leafy greens, or vegetables.

Alternatively, you can also mist your plants during the day to increase humidity levels and lower temperatures in the tent during the hot summer months.

Tips for Monitoring and Maintaining Humidity Levels in Your Grow Tent

Keeping a close eye on humidity levels in your grow tent is an important factor in keeping your plants and flowers healthy and flourishing. High or low humidity levels can lead to wilting, rotting, or even death of the plants.

Let’s take a look at some of the cheapest and most effective methods.

  • Check the humidity levels regularly using a reliable hygrometer. Keep the humidity level between 40% to 60% for optimal growth.
  • Increase ventilation and airflow in your grow tent by adding exhaust fans or oscillating fans. This helps to remove excess moisture from the air.
  • Adjust the temperature of your grow tent to maintain a comfortable level for your plants. A cooler temperature can help to reduce humidity levels.
  • Use a grow light that emits low heat to prevent excessive evaporation from your plants.
  • Water your plants in the morning to allow sufficient time for the soil to dry before the humidity levels rise at night. Do not overwater your plants as it can lead to mold and other issues.
  • Consider using natural options such as charcoal and baking soda which help to absorb moisture from the air. Place them in a container within your grow tent.

Final Thoughts


Many people choose to grow marijuana or other plants indoors, as it is a more controlled environment with limited exposure to wind and other elements. Growing inside allows you to control all aspects of the plant’s growth, including temperature, water and lighting.

Controlling humidity is another important factor to consider when growing indoor plants. Maintaining the right temperature and humidity levels can help ensure your plant's health. Cannabis plants love warm and dry environments, so it's important to provide the right conditions for your plants.

You can use a hygrometer to track the humidity in your indoor environment. Using a good dehumidifier for grow tent & room is always the best idea to help control humidity. However, if you don't have a budget for investing in a dehumidifier, try a few different methods mentioned in the post to ensure optimal levels of humidity and temperature.

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My name is Justin Williams. I am the founder and blogger at TheDehumidifierExperts.com (read more about us). I was an allergy sufferer and that is also the reason why I began my trek to finding the best dehumidifier for my own personal health issues. All of the dehumidifier top picks on the site were put through their paces by Lance Perez - our dehumidifier researcher. He put each one through a series of tests to see how well they performed. Then, our editorial team compiled the insights into articles and published them.

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