How To Increase Humidity In A Grow Tent (9 Easy Ways)!!!

Maintaining the right level of humidity in a grow tent is inevitable for growing plants properly. 

If the humidity level of the grow room starts decreasing or getting low, your plants won’t be able to keep pace with the humidity loss. Consequently, the plant can’t grow naturally, which halts the natural growth of your plant.

You may try turning your light up to 100% to raise the temperature. But what do you do if the humidity falls to 22% or lower? How to increase humidity in a grow tent?

Yeah, you can use a humidifier. But it is not the only way to increase the humidity level. There are hundreds of methods available to raise humidity. Among them, we enlisted 9 effective ways to increase humidity in this guide. Now, let’s take a look at them.

How To Increase Humidity In A Grow Tent

What Is Humidity And Relative Humidity?

Simply put, the amount of water vapor air can hold is called humidity. You can measure humidity in the following ways — relative, absolute, and specific. 

And since you are into indoor gardening and Relative Humidity is the most convenient option of all, let’s get to know a bit more about it. 

The relative humidity or (RH) is a percentage measuring how much water vapor is present in the air, in comparison with how much water could be held in the air at that certain temperature. 

For instance, relative humidity of 50% means the air is holding one-half of the vapor it can hold. Relative humidity shouldn’t be higher than 75% and lower than 20%.

What Is The Right Humidity Level?

The humidity requirement for plants depends on the various stages of their growth. The ideal humidity levels inside your grow room for every growing stage are as follows:

  • Seedlings or Clones require 70% – 75% humidity 
  • Vegging plants prefer 50% – 60% humidity
  • Flowering plants prefer 40% – 50% humidity 
  • Harvesting requires 45% – 50% humidity

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9 Ways To Increase Humidity In Your Grow Tent

1. Use a Humidifier

Of all the options, the easiest way to elevate the humidity level is buying a humidifier for your grow tent. A humidifier extracts a cool mist that is important for your plants’ development and thus helps in raising humidity levels inside your grow tent. 

If you own a humidifier, then consider increasing its moisture level to 50% to 65% at the least. Plus, always put the humidifier on the bottom shelf of your grow tent to keep it away from spraying mist directly on the grow lights.

I strongly recommend you purchase a humidifier with a built-in humidity, allowing the machine to turn off automatically as per your preferred moisture settings.

Keep in mind that you have to control the humidifier. Because if you run a humidifier on full power continuously within a confined space, it will keep increasing the humidity level to a great extent, which will therefore pose a great threat to your plants.

Hence, you’re better off getting the best-quality humidifier for your growing space that will help you control the temperature and airflow with ease. Or, you can make use of a humidity meter to check out the RH level of your grow tent timely.

2. Combine Some Younger And Larger Plants

If you cannot boost up the humidity inside your grow tent, then start increasing plant density. While plants respire, they emit water vapor and carbon dioxide. So if you expand the number of plants, your grow room gets increased vapor, and eventually, the RH of your grow tent also keeps increasing. 

Most importantly, try to add some bigger plants to your grow room as they have lots of bigger leaves that discharge a massive amount of carbon dioxide and water vapor. And, both of these products help in growing smaller plants.  

However, avoid overcrowding your grow room with larger plants to make sure the younger plants get the needed amount of nutrition, air, and light.

3. Lower The Speed Of Your Fan

Venting your grow tent properly is vital to control relative humidity inside your grow space. Proper ventilation also ensures your grow tent has an exchange of air.

In addition, fans circulate the air well and distribute the air to your grow plants. Proper air circulation helps you prevent bacteria and fungi from forming inside your grow room or tent as well.

Typically, people prefer to set the fan at a moderate speed to preserve moisture at various phases of plant growth.

However, mind you, if you set a fan at full speed, then the fan will dry up the air faster than normal. A high-speed fan will also prevent the vapor from sitting on the leaves’ surface for absorption. High-speed fans can therefore cause dehydration to your plants. 

For this reason, consider setting the speeds of your fans at the lowest level, as the low speed circulates less air and will help eventually boost up the humidity inside your grow tent. I would suggest setting a fan at 60 percent to make sure the RH level.

4. Eliminate Half Of The Fluorescent Lights

Removing half of the fluorescent tubes is a simple yet most overlooked solution to enhance the humidity inside your grow tent or room. As we know that when humidity decreases, temperature increases. And since fluorescent lights release heat, they reduce humidity. 

5. Make Use Of A Swamp Cooler

Using a swamp cooler, you can also lower the temperature in your grow space. The cooler starts functioning while your grow room’s temperature is too high and humidity is too low. Remember, this machine cools the air down and raises the humidity level at the same time.

6. Add Water

Adding water to your grow tent to control the humidity level is an easier and great option. As we have already known, the more water surface you provide to your grow room, the more humidity increases. 

And, to create more water surfaces, all you need to do is just put bowls or buckets of water on your grow room’s floor. 

You can also enhance the humidity by hanging some wet towels around inside your grow room or tent. If your grow tent is 4×4 feet, then 2 wet towels will do the trick. 

After hanging the soaked towels on the first day, check them out every 2 hours. If you notice the towels drying up faster, that means that there is less humidity in the air. 

You will have to consider adding up more wet towels if your towels take less than 4 hours to dry up. Because according to an equation, a towel’s average drying time is 4 hours. Plus, when you hang the towels, make sure they do not hamper airflow. 

Additionally, keeping wet sponges next to every grow tray will also make you able to raise the humidity levels near the growing plants. 

Bear in mind that, though a wet towel or a water container helps you boost up the humidity a bit, it cannot create your desired RH.

7. Make Your Own Propagation Set-Up

This method helps you in increasing the relative humidity by extracting a cool mist in your grow room. Just buy an adjustable extractor that has a built-in thermostat. The extractor pulls out the air and thus controls the temperature.

For the installation process, just place a water bucket on top of your grow tent. The water in the bucket will then be moved into a humidifier through a hosepipe. A cool-mist will soon start entering your grow room and the RH inside the room will raise gradually. 

8. Put An Air Conditioner Into Your Grow Tent

If you can’t raise the humidity level inside your grow tent following the above tricks, then you will need to switch to using an air conditioner. If you already have one, just increase the temperature of your AC. Though it is a costly option, I can bet it will be worth the money for sure. 

Or, if you’ve got an air conditioner that doesn’t operate well, purchase a new one that will properly take the temperature of your grow room down.

9. Use Water Spray Bottle

Every indoor grower typically owns spray bottles. Another super easy-to-follow method to raise the relative humidity is spraying water every morning and evening on the walls inside the grow tent.

Final Words

Well, there you have it, people. Take a deep breath and pat your back, as you’ve just finished reading a 1500-word article on how to increase humidity in your grow tent.

To sum up, controlling and increasing humidity inside your grow tent is one of the prerequisites for your plants’ overall growth and having a good yield. All of the aforementioned methods are cost-effective. All you need to do is just choose the best option that will work best for your grow tent.

If you can afford, consider purchasing a humidifier or an AC, but if you don’t want to go down that road, you can go for the easy DIY methods I’ve explained above.  

And, did I miss anything in the article? If so, please do let me know in the comments section below so I can update the article further. Happy growing, thanks!!!

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