Why Is My Grow Tent Wet Inside? What Humidity Level Should My Grow Tent Be?

by Lee Safin

Many of us use grow tents when we plan to have indoor growing. Since it is not natural, you want to ensure a perfect humidity level inside the grow tent. Otherwise, your plant won’t grow in its fullest possible manner.

So, Why is my grow tent wet inside?

Grow tent may become wet for several reasons, such as overwatering your plants, higher temperature inside the grow tent, planting over-transpiring plants, etc.

The air inside the grow tent holds more water vapor by collecting water from the plant soil and plant leaves. More humidity means more water vapor.

If you are interested in learning more precise details about “Why is my grow tent wet inside?” keep scrolling until we finish.

Why Is My Grow Tent Wet Inside? What Humidity Level Should My Grow Tent Be?
Why Is My Grow Tent Wet Inside? What Humidity Level Should My Grow Tent Be?

Why Is My Grow Tent Wet Inside?

Conversion of water droplets is incurred from water vapor if your grow tent is wet inside. It is also called condensation.

So, what are the early signs of wet grow tent?

You will notice water droplets on your plant stems, foliages, and other areas before your grow tent becomes wet. They will move to the upper parts gradually.

So, you are here to know, why is my grow tent wet inside? Grow wet becomes wet for several reasons, as we already mentioned.


Plant soil only retains a certain amount of water that is necessary. The excessive soil will go under the soil.

Since your plant doesn’t have too deep soil ground, the extra water will move from the soil to the atmosphere.

As there is limited space, it will make the internal area of grow tent wet over time.

Higher Temperature

Your grow tent must have a balanced temperature for the optimum growth of plants. It should be neither lower nor higher.

Higher temperature retains more water vapor. An excessive warmer environment inside a grow tent will raise the humidity level.

A high humidity level increases the chance of holding more water vapor. As a result, the flow of water vaporization boosts up, making the grow tent wet quickly.

Over-Transpiring Plants

Sometimes, plants’ transpiration rate may increase heavily. This makes them losing more water than intaking. If it goes on for several days, it will make the plants sick within a short time.

When the transpiration rate rises more than average, more water vapor is accumulated on the surrounding air inside the grow tent. Therefore, grow tent becomes wet after a certain time.

So, these are the main causes if you are wondering about “Why is my grow tent wet inside?”

How To Raise Humidity In A Grow Tent (And Why You May Not Need To)?

Wondering how to increase humidity in a grow tent?

This is an uncommon question. Most of the time, we face difficulty in decreasing the humidity level. But, a certain situation may arise when you have to do it.

You have a few ways to achieve this. Improving the ventilation system is the most convenient solution to solve this issue.

Spend more time to ventilate the internal area of the grow tent. It will help to retain a sufficient amount of moisture inside the grow tent.

SkyGenius Battery Operated Clip On Mini Desk Fan, Black
SkyGenius Battery Operated Clip On Mini Desk Fan, Black

Keeping a big water container inside the grow tent is another easy-going option. Set up a clip-on fan close to a water reservoir. The overall moisture level will increase when water blows throughout the area.

However, it requires monitoring. Overdoing it will lead to mold/mildew, and you may lose control of the situation. Since it is a manual approach, inspection is always necessary.

If you don’t mind spending some money, get a grow tent humidifier.  Just like a dehumidifier decreases the humidity level, a humidifier raises the level of hydration.

Using a humidifier allows you to raise the moisture level if the plants become excessively dry. Just confirm that you pick the most suitable one to avoid overdoing it.

Will Mold Grow At 55 Humidity?

When the humidity level increases more than average, it has more probability to cause black mold or sooty mold issues. Black mold means an infestation of aphids; it is also called a fungal disease.

Will mold grow at 55 humidity?

If the humidity level of the plants’ surrounding area exceeds 55%, it may encourage mold growth. Experts recommend keeping the humidity level between 40-70%. But always keeping at more than 55% may cause mold growth sometimes.

Grow tents or grow rooms don’t always have a stable temperature. That’s why growers often use various machines to control the temperature.

So, why does this happen? The HVAC system is the main reason behind the fluctuation of humidity levels. In fact, different areas of your grow room may have different humidity levels.

Does a carbon filter remove humidity?

Besides knowing about “Why is my grow tent wet inside?” you should also know this question: Does a carbon filter remove humidity?

A carbon filter mainly removes odors or any unpleasant smells from indoor air to keep it fresh.

Does a carbon filter remove humidity?

Carbon filters can reduce humidity to a certain degree. However, since it was not designed for that purpose, you should not use it. When they collect moisture from the air, they will fail to remove odors. Hence, their main function is disrupted.

If you wish to reduce humidity from your grow tent or other indoor areas, use a humidifier. It is designed for that purpose. Using a carbon filter to remove humidity may damage the machine completely.

What Humidity Level Should My Grow Tent Be?

Do you think plants always need the same humidity level regardless of their age?

NO! They need different humidity based on their life stages.

Cuttings and seedlings require around 70-75% humidity since their roots system are weak and not grown properly. Having higher-level humidity makes their root system strong and boosts growth.

Baby plants also need a higher level of humidity, approximately 65-70%. That’s why you will always see many growers use humidity domes or seed starting trays to ensure sufficient moisture.

3-Set Strong Plant Growing Trays With Humidity Domes For Seed Starting, Germination And Seedling Propagation, Holds 144 Cells In Total (Cell Tray Not Included)
3-Set Strong Plant Growing Trays With Humidity Domes For Seed Starting, Germination And Seedling Propagation, Holds 144 Cells In Total (Cell Tray Not Included)

But when they grow a little bit, their intake for humidity will drop. It will be around 50% to 70% because they have grown enough to absorb water from their root systems and foliages.

The humidity level of plants varies based on their type. For instance, the humidity requirement for vegetable plants is around 50%-70%, while 40%-50% for flowering plants. Flowering plants thrive best in low humidity levels.

If you plan to grow harvesting-type plants, the humidity level should be 45% to 50%. Excessive moisture will prevent them from thriving in the best possible manner.

So, let’s know them in a table:

Plant type Humidity Level
Cuttings /Seedlings 70%-75%
Baby Plants 65%-70%
Vegetable Plants 50%-70%
Flowering Plants 40%-50%
Harvesting-type Plants 45%-50%

Why Is My Humidity So High In Grow Tent?

Many growers experienced a situation like having excessive humidity in grow tent. Do you think it comes unexpectedly? Absolutely not!

It could have a reason, and you want to figure out it soonest. Here are a few possible reasons if you are wondering about “Why is my humidity so high in grow tent?”

Water Reservoir

CHERAINTI Hydration Bladder 2 Liter Water Reservoir, Water Storage Bladder Bag, Hydration Pack Replacement, For Hiking Biking Climbing Cycling Running, Large Opening, Green
CHERAINTI Hydration Bladder 2 Liter Water Reservoir, Water Storage Bladder Bag, Hydration Pack Replacement, For Hiking Biking Climbing Cycling Running, Large Opening, Green

Have you placed any water reservoir close to the grow tent or inside it? The mess is more if it is open. Apart from that, any typical water container or nutrient reservoir can also promote water vapor.

The more water vapors into the atmosphere, the higher the humidity level. The worst situation can be if you have kept an oscillating fan inside the grow tent to provide sufficient airflow.

Humidity Is High Outside

Humidity level varies from one state to another. If your surrounding area has a high humidity area, it will affect your grow room humidity level too.

Growing plants in grow tents at high humidity levels is a challenging task. Using a wide of things helps you controlling the humidity fluctuation inside the grow tent.

Any small leakages on the grow tent will allow the outside temperature to enter inside it. As a result, all your effort to control humidity levels will go in vain.

But if the humidity is in an ideal condition in the outside environment, it won’t cause any issues.


Overwatering means more water accumulation on the soil. The excess water that plants can’t absorb will move to air through vaporization.

So, avoid watering excessively. Give water only when needed. It prevents wet soil.

Higher Transpiration

Plants foliages become bigger when the plant size increases. According to researchers, bigger foliages will breathe out a higher amount of vapor in the atmosphere.

That’s why coping up with such a situation is necessary. Otherwise, you will experience higher humidity in your grow tent. Additionally, adding more plants inside the grow tent may also cause this issue.

Will Turning up The Heat Reduce Humidity?

Temperature and humidity have a close relation. Higher temperature makes the weather warmer. As a result, the percentage of water vapor increases, and finally, the humidity level increases.

Will turning up the heat reduce humidity?

Absolutely not. Turning up the heat promotes warmer air and helps the air retain more humidity. Hence, the air will hold more water vapor for being warmer, meaning increased humidity.

So, how will you reverse the situation to reduce humidity? The temperature must be changed to accomplish it. In humid climates, moisture is more abundant. So your goal is to lower the air’s humidity.

It can only be possible when the temperature is cold enough. Not excessively. Too low temperature may harm plant growth.

How Do I Lower the Humidity In My Grow Room?

So, you are here to know how do I lower the humidity in my grow tent? High humidity is not only bad for plants but also for other creatures.

Controlling the humidity is essential. However, remember all plants don’t need the same level of humidity. You want to lower the moisture up to that level, which is suitable for them.

Here we are mentioning the effective ways to lessen the humidity in the grow tent. Just follow them if you are wondering about “How do I lower the humidity in my grow room?”

1. Water When Necessary

Many new growers panic themselves watering their plants more frequently. It does damage instead of doing any good.

Pick e perfect time and take an ideal amount of water to use them on plants. Only then will it promote ideal transpiration based on your grow room temperature.

But excessive watering slows down the transpiration rate and reduces its overall efficiency. Your plant won’t grow in the fullest possible manner due to saturation with water vapor. So, water wisely.

2. Stripping Of Leaves

Stripping leaves from your plants is another way to lower humidity. How? Smaller foliages of plants can’t retain as much moisture as the bigger foliages can do.

Hence, if you notice some plants have a large amount of bigger laves, remove them. It will reduce the moisture level up to a certain level.

3. Ventilation

Air is important for plants. If the humidity level is excessively high, they need more air. Enough ventilation will absorb the high moisture to an extent. Also, it reduces humidity.

Creating an opening in your grow tent is a good idea to allow an adequate amount of air to enter. But avoid making a too large hole. Otherwise, it will reduce the humidity level too much, and your plant will face issues.

It should be noted that the unique smell inside the tent may spread outside for frequent opening. If you set up the grow tent in your storeroom, rodents may attack the plants through the opening.

 4. Utilize a Dehumidifier

Waykar 2000 Sq. Ft Dehumidifier For Home And Basements, With Auto Or Manual Drainage, 0.66 Gallon Water Tank Capacity
Waykar 2000 Sq. Ft Dehumidifier For Home And Basements, With Auto Or Manual Drainage, 0.66 Gallon Water Tank Capacity

A dehumidifier is one of the most commonly used items to reduce humidity. You can purchase a special dehumidifier only designed for grow tents.

The device reduces your activities. You just install it inside the grow room and let it do the job. The only thing you do is removing water from the container when it becomes full.

This device is particularly helpful when you don’t want to give more effort and time to reduce humidity. Additionally, applying several solutions may decrease the moisture too much.

Neither too much nor too low humidity is good for plants. Keeping the right humidity level is mandatory for optimum growth.

So, these are the four approaches you can follow if you are wondering about “How do I lower the humidity in my grow tent?”

How Do You Control Temperature And Humidity In A Grow Tent?

For plants to flourish, it is essential to keep the temperature and humidity controlled in a grow tent.

So, how do you control temperature and humidity in a grow tent? After talking with several expert growers, we have finally found some fruitful tips

Make Use of a Humidifier

When your grow tent doesn’t have enough moisture, you can make use of a humidifier. The machine is connected to a water container. The humidifier receives water through the pipe. Then, the device spreads moisture to the entire room.

The machine is effective enough to handle the moisture. You don’t need to use other things to increase the moisture level of your grow room. Since it is a pricey option, not everyone can afford it.

Lowering the Dehumidifier’s Settings

Do you have any special fan that can remove moisture? If yes, lower the settings to prevent removing an excessive amount of moisture. Therefore, an adequate amount of humidity is sustained to boost plants’ growth.

Keep Bigger Plants

Bigger plants have bigger leaves. They can transport higher levels of moisture compared to small leaves. So, they are less likely to become dry than small plants.

Additionally, you can make a group by clustering several plants together. Therefore, they work together to extract moisture from the grow room.

You can count it as a small humidifier that doesn’t require any machine. However, make sure all the grouping plants are free from diseases. Otherwise, all the closed plants will be affected by even a single one. Test their health first.

Use Less Grow Lamps

How many grow lamps do you use in your grow tent? As you know, each grow lamp generates heat. This makes the internal condition dry, and the humidity level also decreases.

Keeping more grow lamps increases the overall heat. Choose to grow lamps that are bright and don’t generate too much heat. So, you won’t need too many grow lamps if a few of them ensure enough light.

Handle Air Flow

The more airflow you allow inside the tent, the more moisture will be blown away. Restrict the airflow if the moisture level drops significantly. This will enable plants to hold the moisture to an adequate level to make an advantageous environment for the plant.

Track Down the Humidity Level

The humidity level should not increase or decrease excessively. For that, monitor it regularly. If necessary, use a device to measure it.

So, these are all tips you want to follow to get a clear idea about “How do you control temperature and humidity in a grow tent?


When using grow tents for growing plants, they need extra care. Special care ensures proper growth. Also, it keeps the plant free from diseases. Make certain you keep the perfect level of temperature and humidity in your grow tent.

Are you still wondering, “Why is my grow tent wet inside?” Hopefully, this guide covered “Why is my grow tent wet inside?” in greater detail.

Last update on 2022-01-28 / Affiliate links / Images from Amazon Product Advertising API

About Lee Safin

Lee Safin was born near Sacramento, California on a prune growing farm. His parents were immigrants from Russia who had fled the Bolshevik Revolution. They were determined to give their children a better life than they had known. Education was the key for Lee and his siblings, so they could make their own way in the world. Lee attended five universities, where he studied plant sciences and soil technologies. He also has many years of experience in the U.S. Department of Agriculture as a commercial fertilizer formulator.

Thoughts on "Why Is My Grow Tent Wet Inside? What Humidity Level Should My Grow Tent Be?"

Now you can get FREE Gifts. Or latest Free Gardening Books here.

Disable Ad block to reveal all the freebies. Once done, hit a button below