How To Keep Humidity High In Grow Tent

How to Increase Relative Humidity in a Grow Tent

Documentation Download Documentation Download Documentation Grow tents are incredible instruments that allow you to have complete control over the environment in which a plant grows. They are great for growing plants in your house, but they can be tough to handle due of the high humidity levels they produce. Many plants, particularly seedlings and cuttings, require extremely high levels of humidity to thrive. Relative humidity is a measurement of the quantity of water vapor in the air, and there are numerous simple ways to raise the level of relative humidity.

  1. In order to increase humidity more rapidly, moist sponges should be placed in the tent. Soak the sponges in water, then place them near any fans or air vents in your tent to help circulate the air. Over time, the heat and air movement will cause the water to evaporate, raising the relative humidity in the air. When the sponges get dry, you can either re-use them to maintain the humidity or remove them from the room to allow the humidity to drop again.
  • Sponges dry out more quickly than bowls of water, resulting in an increase in the amount of moisture in the air. It’s also possible to put them closer to your plants and lightbulbs in order to distribute moisture more rapidly
  • Another alternative is to place sponges inside of bowls or trays that have been filled with water. It will hasten the evaporation of water
  • When used in tiny, vertically oriented tents with shelves, sponges perform nicely. Despite the fact that these tents don’t have a lot of room, you can generally squeeze the sponges in between the plants on the shelves.
  • 2 Place water bowls inside the tent for a more gradual increase in temperature. Fill up bowls or trays in the sink, then spread them around the grow tent to keep it from being too hot. A large intake fan located near the ground on one side of the tent is common. Position one of the containers near the air vent, and then place more containers near adjacent air vents to complete the installation. In order for the water to evaporate, the humidity level must rise.
  • Water bowls are convenient since you can refill them as needed and remove them when they are no longer needed. They are more effective than towels at increasing the humidity of the tent on a constant basis. Bowls should be used in large tents with enough of floor area and ventilation. When used in conjunction with an internal ventilation fan located at ground level, they are the most effective.
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  • s3 Temporarily raising the humidity level can be accomplished by hanging damp towels. Soak the towels in water for a few minutes before spreading them out about the grow tent. Place them near any air vents that are located around the edges of your tent. As air is drawn inside the tent, it will come into contact with the towels. The moisture draining off of the towels raises the relative humidity level in the room.
  • Maintain a safe distance between the towels and grow lights and other heat sources to prevent them from burning. Towels are not intended to be a long-term solution, but they can be used to temporarily increase the humidity level. Towels may be used in any type of tent, as long as you have a place to hang them from the ceiling. The best option is to stay in tall tents with an inside fan that blows air in from near the ceiling to keep you cool. It’s also possible to hang them near air vents that are close to the ground.
  1. 1 Use a humidifier to automatically regulate the humidity level in the air. You may use a regular household humidifier to keep the air in your grow tent moist. Many grow tents are also equipped with ceiling supports from which you may hang a humidifier in order to conserve floor space. Instead of having to constantly monitor the water supply and temperature in your house, consider purchasing a humidifier with automatic settings. The humidifier will discharge water into the air in order to maintain a constant humidity level.
  • Use of a conventional household humidifier will necessitate daily refilling with new water if you want to go that route. Check it at the same time every day, such as every morning, to ensure that it continues to function properly
  • Make certain that you are using a humidifier rather than a dehumidifier. In order to reduce the relative humidity, a dehumidifier must be used to remove moisture from the air.
  • 2 Decrease the speed of the extractor fan to prevent the air from drying out as soon. If there is a ventilation fan near the tent’s ceiling, it will suck stale air out of the tent. It also removes a significant amount of humidity from the tent, so keep the fan running at a moderate level. If you have any additional fans that you use to circulate fresh air between plants, you should also turn them down to a low level as well. If necessary, you might even turn off the ventilation system for a short period of time, such as for around one hour every day, in order to elevate the humidity level more quickly.
  • It is critical to maintain air circulation throughout the tent in order to maintain a uniform temperature throughout
  • Thus, do not turn off the fans permanently. For bigger tents equipped with a ventilation fan with variable speed settings, this method is effective. Some bigger tents also include wall-mounted fans that may be turned down to reduce the heat.
  • 3 Lowering the temperature is a simple method of increasing humidity. Utilize the fact that your plants can tolerate a lower temperature to simply raise the humidity levels in your home or office. If your tent has a temperature control option, make adjustments to it. Alternately, you may install an air conditioner or a water chiller inside the tent to keep it cool. To keep the temperature lower than normal, you might also add fans or turn off the lights.
  • When the temperature is lowered, colder air descends to the bottom of the tent, causing condensation. Warm, moist air will ascend to the surface of the atmosphere, increasing the degree of humidity. Make sure your tent is equipped with a thermometer so that you can keep an eye on the temperature. In addition, maintain the tent well-insulated and well-sealed so that the temperature remains consistent. The temperature settings on higher-end hydroponic tents are frequently programmable. In a smaller tent with plenty of storage, you might not have enough space for an air conditioner or a water cooler.
  • 4 If you have younger plants, turn off half of the lights to help boost the humidity. Shut off the lights and allow them to cool for approximately 5 minutes before turning them back on. A common feature of grow tents is a series of tube lights strung along the top. Remove the bulbs from their sockets and place them somewhere safe. Due to fewer lighting, the temperature within the tent will be lower, resulting in a rise in the relative humidity
  • If your grow tent has many light sources, removing some of the bulbs is a fairly simple technique to raise the relative humidity in the growing environment. Some smaller tents, on the other hand, will not allow you to accomplish this. This method is most effective with young plants. Seedlings are less sensitive to light than adult plants, and this is especially true for young plants. They require more humidity than they do more light, which is why most tents are equipped with replaceable bulb lights. Some low-cost tents, particularly tall and thin versions, may not be equipped with various light sources.
  1. 1 If you have additional space in the tent, you may put larger plants in there as well. Even if you’re growing seedlings, you might want to include some fully-grown plants in your container. If you’re cultivating little herb plants, you may include some taller veggies or blooming plants to break up the monotony of your garden. Maintain a sufficient distance between the plants so that they do not overwhelm one another. Make certain that each one receives a enough amount of light and water.
  • Large plants require more watering than smaller plants, but they also transpire more moisture than smaller ones. The moisture that is released into the atmosphere contributes to an increase in relative humidity. As they grow older, mature plants are able to take in more water through their roots, reducing the amount of water they must extract from the air, as they do with younger plants. Large tents with plenty of floor area are the only ones that will work for this. In some cases, if your tent is tall or has an adjustable height, you may be able to accommodate larger plants in it. Hydroponic tents with shelves are frequently insufficiently spacious
  • 2 If your plants are spread out, group them together near together. Place them directly next to one another so that the leaves do not come into contact. They will still require adequate space to develop. Over time, each plant will release water that the other plants may utilize, causing the overall humidity level to increase.
  • Keep in mind that this will not totally solve the problem of low humidity, and you will still need to do things like water and spray the plants. They will hold more moisture as a result, allowing the humidity level to remain higher than normal. The fact that plants grown in a grow tent are potted means that you won’t have to worry about their roots becoming entangled. Simplest solution is to ensure that the leaves have ample space to get light and moisture.
  • 3 Mist plants with a spray bottle if your plants require a modest boost in the morning sun. Lightly mist both sides of the leaves with water to prevent them from becoming brown. The additional water will cause the humidity level to rise, and your plants will benefit from the fresh water that will be available immediately. When used on seedlings and cuttings, it is most effective since they are unable to absorb water through their roots. If you want to keep the humidity level high for the long term, you’ll have to check back each morning and spritz all of the plants again if the level has dropped.
  • Misting does not significantly increase humidity, therefore it must be done on a constant basis in order to maintain the desired relative humidity level. It is ideal to sprinkle plants first thing in the morning so that the leaves have time to dry during the day. In this way, they won’t become too dripping wet
  • Water is absorbed by plants through pores in their leaves. Make sure you spray under each leaf because the majority of the holes are on the bottom.
  • 4 If you are unable to elevate the humidity level to a satisfactory level, cover the plants with bell cloches. Cloches are domes that are used to assist manage the temperature and humidity levels in the environment around certain plants. Each plant will require its own cloche, which you will need to purchase separately. Plants should be moved beneath the domes, and then the ventilation openings on each dome should be pulled open. Cloches, even when they are open, assist in retaining more moisture.
  • Even something as basic as a plastic bag can be used to increase the amount of humidity in a room or space. For example, you may place them over seedlings. If your grow tent is correctly set up, you won’t need to use any cloches at all. They are most useful in emergency situations or when you need to swiftly elevate the humidity level. Some plants, such as carrots, radishes, peas, and parsley, do very well when grown beneath cloches
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  • If you don’t already have one, invest in a digital hygrometer that you can hang or place inside your grow tent. It keeps track of the relative humidity
  • In general, seedlings need a greater relative humidity than do mature plants. Start with a 65 percent to 70 percent concentration and then reduce it until it is 40 percent to 50 percent when the plants begin to blossom. When the humidity level is too low, the plants begin to dry out, which is harmful. For example, you could observe that the leaves are becoming dark and curled
  • In addition, high humidity levels can be harmful to plants, so keep an eye out for rot or powdery mildew.

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  • Grow tents have a large number of electrical components that are susceptible to harm from water. Make a point of keeping towels, sponges, and any other moist things away from the lighting and heating components at all times.


Things You’ll Need

  • Cooling system or water chiller (optional), humidifier, fan, temperature control, etc.

About This Article

humidifier; fan; temperature control; air conditioner or water chiller (as an optional feature);

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Cooling system or water chiller (optional); humidifier; fan; temperature control; Of course, if the relative humidity within your grow tent falls outside of these optimal parameters, cannabis will continue to thrive. However, if it is too low, yields will decline a little. Furthermore, if the humidity is really low, they will suffer greatly. Given that you have complete control over the atmosphere within your grow tent, why not create the greatest circumstances possible? Naturally, this means that there may come a moment when you will need to raise the humidity in your grow tent to get optimal results.

How To Increase Humidity In A Grow Tent

However, before we get into the best methods for increasing relative humidity in a grow tent, we want to point out that it is possible you will not need to raise it at all. When weed plants are seedlings, they require the maximum levels of humidity possible. There is a fair probability that you are attempting to raise humidity levels because you have seedlings that require a high degree of moisture in the air to survive.

Raising Humidity For Marijuana Seedlings

If your plants are seedlings, we recommend that you do not even bother trying to raise the humidity level in your environment. 70 percent is a challenging quantity to achieve, especially in a large grow tent with a lot of light. Furthermore, it has the potential to cause problems with some of the equipment that may be present in the grow tent. Instead, it is much simpler to construct a smaller, more restricted environment around the seedlings and to raise the humidity solely within this smaller environment, while keeping the humidity in the remainder of the grow area unaffected by the changes.

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It is recommended that you use an apropagator tray with a humidity dome, but you may easily rig something together on your own.

Simply misting the inside of the dome with a spray bottle on a frequent basis will be sufficient to maintain humidity levels.

If your plants are in the vegetative or blooming stages of their growth, constructing a micro habitat will no longer be effective on their behalf. If they aren’t already too enormous, they will be in the near future. It will be necessary to boost the humidity levels throughout the entire grow tent.

Increasing Grow Tent Humidity: Best Methods

There are a variety of methods for increasing the humidity inside your growing environment. We’ll go through all of the greatest strategies with you below so that you can pick which one is the most effective for your situation.

Use A Humidifier

If you need to boost the humidity level in your grow tent or grow room on a constant basis, nothing works better than using a humidifier. It is the most straightforward approach, and you can obtain reasonably decent ones for a reasonable price. There are a few characteristics that you should look for in a humidifier. It should be equipped with a built-in humidistat. You may program it to turn off automatically when the humidity reaches a specified level and turn on automatically when the humidity decreases below that level.

You’ll also want one with a large enough tank capacity so that you don’t have to be filling it up all the time.

If you are unable to locate a nice humidifier that satisfies all of your needs, here is an excellent one available on Amazon that will suffice for a little grow in an area of 4 by 4 feet or less.

Using a humidifier that sprays mist into the air is a wonderful idea, but only if you use filtered water rather than tap water, which may be harmful (this is actually a good idea with any humidifier to be honest).

Add Water

A less complicated method is to simply add water to your grow tent as needed. This can be accomplished by placing some bowls, buckets, or other water-holding containers on the floor. Alternatively, you may put a damp towel (or several) inside the tent to keep the bugs away. It goes without saying that this approach is less precise than utilizing a humidifier when it comes to obtaining and maintaining the desired humidity level. You’ll have to keep an eye on it and make adjustments until it’s exactly where you want it.

Reduce Ventilation

Humidity is increased in two ways when there is insufficient ventilation. For starters, the circulation of air within the tent helps to dry up any moisture. Second, moisture is carried away by the air that is vented out of the tent by the extraction fan. Of course, there are some situations in which it is not possible to reduce the volume of air that is vented out of the tent. For example, you could be coping with heat-related problems. You should always make sure that you have enough fan power for the size of your grow tent.

Although it is possible to lessen the power of your extraction fan without causing additional problems, this is a simple method of increasing the relative humidity within your grow tent. All of the top grow tent fans offer a variety of speeds.

Reduce Temperatures

Because colder air does not require as much moisture content to get saturated as warmer air, lowering the temperature in your grow tent will also raise the relative humidity in your grow tent. Obviously, you don’t want to resort to reducing the temperature if doing so would result in the temperature dropping below the optimal range for your plants and their present growth stage. For cannabis, this implies that you should avoid going below the following temperatures throughout each stage of growth:

  • Climate: 73° F (23° C) for seedlings
  • 70° F (20°C) for vegging
  • 65° F (18° C) for flowering

Effects Of Low Humidity On Cannabis Plants

Plants do not just absorb water via their roots; they also transpire water. They also obtain water by the extraction of moisture from the air by means of their leaves. If there is no moisture in the air, plants will be unable to obtain water in this manner and will be forced to rely only on their roots for water. When it comes to young plants in particular, this can be an issue. Clones do not yet have a well-developed root system, therefore they must obtain the majority of their water from the surrounding environment.

  1. If the relative humidity is too low, clones may not be able to root at all or only partially.
  2. During vegging, plants receive more water from their roots, but they still rely on the water provided by their leaves to survive.
  3. It can also induce nutrient burn, which can result in yellowing leaves and, in the worst case scenario, the death of your plants.
  4. Why does this happen?
  5. Understandably, it is critical to ensure that your weed plants are growing in the proper humidity conditions.
  6. However, you must be careful not to raise the humidity levels too.

Effects Of High Humidity On Marijuana Plants

bud mold or rot is the most serious hazard connected with excessive humidity levels. Find out what mold on cannabis looks like in this article. Obviously, this only occurs during the flowering stage, when the buds are developing. You should keep humidity levels as low as possible during flowering since it is the primary cause of bud rot. In addition to low humidity, excellent ventilation is required to ensure that moisture does not build on the buds’ surfaces. Using the proper size smart pots might assist to prevent this problem.

The fact that it may grow on plants of any age implies that they are more vulnerable during the early developmental stages of their development, when humidity is higher.

In order to avoid this, make sure that there is adequate ventilation in your grow tent. An oscillating fan is ideal for this application. Even when the humidity levels are high, the airflow prevents moisture from collecting on the plants’ surfaces.

Raising Grow Tent Humidity: Final Thoughts

Low humidity, particularly in the early stages of growth, can seriously impair the development of your plants. But proceed with caution. High humidity has the potential to make things worse. If your humidity level is dangerously low, invest in a humidifier and boost it; but, if it is dangerously low, you could be better off doing nothing. Being a bit low won’t have much of an impact, while being too high would. As is often the case, keeping things simple is the best approach. Learn how to keep things as easy as possible when cultivating marijuana in your home.

How to Increase Humidity in Your Grow Tent (10 Easy Ways)

The most recent update was made on January 18, 2022. It is not difficult to develop a cannabis plant from seed to harvest. With order to develop that perfect sticky icky that is coated in crystals and that generates a gorgeous, potent high, you’ll need to make sure that you take care of specific elements in order to maintain your plants growing at their healthiest and happiest possible. Even while temperature, nutrition, light cycles, and other important factors are easily recalled, there is one more thing to keep in mind: relative humidity.

However, understanding the humidity requirements of your plants is only a tiny part of the struggle.

Increasing the humidity in your grow tent is important for keeping your plants happy and ensuring that they achieve their full potential.

Understanding Relative Humidity

On the surface, humidity appears to be a rather straightforward idea. What percentage of moisture is present in the air? However, there are a variety of methods for measuring humidity. If we’re talking about horticulture, we’re going to be paying close attention to relative humidity. In other words, what exactly is relative humidity? The quantity of moisture in the air in relation to the temperature of the surrounding environment is referred to as relative humidity. According to how hot or cold it is, varying degrees of moisture can be retained by the atmosphere.

The percentage of the total volume of water that the air can hold at any given moment is stated as a percentage of the total amount of water that the air can hold at any given time, up to 100 percent.

Condensation, dew, fog, and other types of moisture are the outcome of this process.

Similarly, if the temperature rises but the total amount of moisture in the air remains constant, the relative humidity percentage will decrease because the air is now capable of retaining a greater volume of moisture.

Factors That Affect Relative Humidity

All of the activities taking on in your grow tent might have an impact on the relative humidity levels within. Each of these elements has an impact on it on its own, but they also interact with one another to alter it.


As previously stated, altering the temperature of an environment will likewise alter the relative humidity of that environment. In a grow tent, fans and lighting help to regulate the temperature, which is important for crop growth. The heat produced by the lights might cause the relative humidity in the grow chamber to decrease. However, not all lights generate the same amount of heat. Compared to metal halide or high-pressure sodium lights, modern LED lights generate far less heat. Therefore, the relative humidity of your grow tent will be less affected by their presence.


The amount of ventilation and airflow in your grow tent will have a significant impact on the relative humidity within it. If the air is exchanged too fast, it might dry up and cause the surrounding environment’s humidity to drop significantly. However, if there is insufficient ventilation, the air will stagnate and the humidity will grow.


Given that humidity is a measure of the amount of moisture in the air, it stands to reason that having more water in the environment would result in a greater degree of moisture. The greater the size of your water sources, as well as the amount of water present in your grow tent, the higher the relative humidity levels you will experience in your grow tent.

How Much Humidity Do Cannabis Plants Need?

Following our discussion on relative humidity, as well as some of the elements that might influence the humidity levels in your grow tent, let’s talk about how much humidity your cannabis plants actually require. Most of the water that your plants take in will be through their roots, but they will also absorb a little amount of the moisture in the air through their leaves. This frees up their roots, allowing them to better absorb the essential nutrients they require to develop and thrive. However, the humidity requirements of your plants will fluctuate as they progress through their life cycle.


When your plants are just getting started and are still rather little, their root systems are not yet matured enough to handle large amounts of water. The result is that they will be absorbing significantly more water via their leaves, and the humidity levels must be high enough for them to adequately hydrate. Temperatures should be in the range of 65 to 80 degrees Celsius for these young plants.

Vegetating Plants

Once your plants have progressed past their first development stage and are ready to begin vegetating, you’ll need to lower the humidity in your grow tent to ensure that they thrive. Humidity levels between 55 percent and 70 percent should be sufficient at this point. Keep in mind that each strain has its own set of preferences, so these values are only a starting point for your research.

Flowering Plants

Now that your plants have made it through the vegetative stage and are ready to blossom, they’ll be requesting even lower humidity levels as they prepare to bloom. As soon as they begin to blossom, you should reduce the humidity to someplace in the 40 percent to 50 percent range.

The humidity in their habitat should be reduced gradually as they progress through the flowering stage until the relative humidity is between 30 and 40 percent by the time they are ready to be harvested.

Young plants, seedlings, and clones Vegetative stage Early flowering stage Late flowering stage
65-80% 55-70% 40-50% 30-40%
  • Additionally, see:7 Top-Rated Ceramic Metal Halide (CMH) Grow Lights – Reviews The Best of the Best

The 10 Ways How to Raise the Humidity in Grow Tents

Having established what elements influence humidity and the estimated amount of humidity your plants will require at any stage of their development, let’s move on to specific methods of increasing humidity within your grow tent.

1. Add More Plants

During a process known as transpiration, plants are able to “breathe.” To put it another way, they’re excreting water vapor via their leaves after receiving it through their root systems. As a result of this transpiration, the relative humidity increases. Increasing the number of plants in your grow tent will increase transpiration, which will in turn increase the humidity in your grow tent. These plants, on the other hand, do not have to be cannabis. Any form of huge plant will aid in the growth of humidity in the environment.

2. Reduce Ventilation

Don’t turn off your ventilator fans totally; instead, turn them down to a low level. Your plants want fresh air and circulation, but an excessive amount of airflow will dry up the air and dehydrate your plants. Reduce the airflow and allow the humidity to rise as a result of this.

3. How to Increase Humidity in Your Grow Tent

It may seem little, but hanging some damp towels near the air entrance of your grow tent is an excellent method to give moisture to the air in your growing environment. During the passage of air over and through the wet towels, it will take up and cling onto the water contained inside them, raising the humidity level in your grow tent.

4. How to Increase Humidity in Your Grow Tent

Because plants in the early stage of their lifecycle require the greatest amount of humidity to grow, you’ll need a means to keep them moist and content. Fortunately, propagators make this quite simple. It’s similar to a little plastic dome that keeps all of the moisture contained within it. You’ll see water droplets accumulating on the lid as a result of condensation; this is evidence that your seedlings/clones are receiving adequate humidity.

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5. Add a Humidifier

What do we do when we need to increase the humidity in our homes? We add a humidifier to the mix. In other words, what works for ourselves will work for our plants as well. Adding a humidifier to your grow tent is an excellent method to rapidly enhance the amount of humidity in the environment. With a humidifier that has many various settings to select from, you can even alter the humidity level to fit the changing demands of your plants as they progress through their development cycles.

6. Reduce the Heat

Because hot air can store more total water than cool air, a hotter tent will have lower relative humidity than a cooler tent with the same quantity of moisture in the air. You may enhance the relative humidity by removing some of the heat from the air. Try removing one or more of your lights from your grow tent to see how much of an impact it has on the humidity of your grow. If you’re using several lights, try removing one or more of them to see how much of an impact it has on the humidity of your grow.

7. Spray the Walls of Your Tent

Every day, spray the walls of your grow tent with a basic spray bottle to keep the bugs away.

When these water droplets evaporate, they will contribute to an increase in the relative humidity of the tent. It is possible to increase the humidity even more by spraying more water or applying it many times during the day.

8. Use a Swamp Cooler

Swamp coolers cool the air by adding moisture to it while simultaneously lowering the temperature. As a result of the fall in temperature, there is more water in the air, as well as a greater relative humidity as a result.

9. Add Water Sources

More water sources imply a greater number of sources for moisture to emerge. Adding a bucket of water or numerous small containers of water to your grow tent will cause more water to evaporate, which will result in more moisture being released into the air.

10. Cool the Tent Down

Adding an air conditioner to your grow tent will result in a fall in temperature, which will be countered by an increase in relative humidity. This is a straightforward method of increasing humidity without the use of water. However, if you make the climate too chilly for the plants, they may not appreciate it as much.


Your cannabis plants’ humidity requirements will change as they progress through the many stages of growth that they will experience. If you want to create the greatest blooms and the largest harvests possible, you’ll need to make adjustments to the humidity levels in your grow tent to match these shifting requirements. The changing requirements of your plants during their life cycle have been highlighted, from the high humidity requirements of seedlings and clones to the significantly reduced requirements of blooming plants.

The final point to mention is that we discussed ten distinct ways that you may raise the humidity in your grow tent right now.

Featured Image courtesy of TinaKru and Pixabay.

Humidity: Finding the Sweet Spot for Your Grow Room

Your cannabis plants’ humidity requirements will change as they progress through the various phases of development. If you want to create the greatest blooms and the largest harvests possible, you’ll need to make adjustments to the humidity levels in your grow tent to match these shifting demands. The changing requirements of your plants during their life cycle have been highlighted, from the high humidity requirements of seedlings and clones to the significantly reduced requirements of blooming plants.

Finally, we discussed 10 distinct ways that you may immediately enhance the humidity in your grow tent.

Featured Photograph by TinaKru, courtesy of Pixabay.

Where’s all that grow room humidity coming from?

Moisture content is a measure of the quantity of water vapor present in the air. Despite the fact that water vapor is constantly present in the air, the temperature of your grow room has an impact on the presence of humidity in your garden:

  • The higher the temperature in your grow room, the greater the amount of water vapor that can be held in the air. Heat also causes water to travel more quickly through the air, covering a larger surface, resulting in increased humidity levels in the grow room. When there is a lot of moisture and it gets hot (as in swamps), it becomes sticky and humid because there is warm water in the air and it is moving swiftly. Conversely, the lower your grow’s temperature, the less water vapor it can store. When there is little heat, the circulation of water vapor slows down, covering less surface, and resulting in decreased humidity in the grow chamber. Lower temperatures can be challenging because too much moisture can result in moisture build-up and/or freezing
  • Too little moisture can result in a bone-dry environment, similar to that of the desert in winter.

The carbon dioxide (CO2) that plants naturally emit can raise the temperature of the grow room, which will result in moisture accumulation, which will boost the humidity. If you utilize CO2 in your grow, the humidity level in your grow room will climb even more. Grow equipment, including as grow lights, can also contribute to the increase in temperature in your grow space.

When the temperature in your grow room is high and the lights are turned off, the temperature will drop. After a significant drop in temperature, you may see moisture accumulating around your lights, which is a symptom of relative humidity variation.

Grow room humidity can’t be that bad, can it?

While a little more or less humidity in your grow room won’t make much of a difference, keeping it between 40 and 70 percent will. However, if you have too much humidity in your grow chamber, you’re in for a world of trouble:

  • The accumulation of moisture and an excessive amount of humidity in your grow room might result in rotting, such as bud rot or bloom rot. Because the findings won’t be seen until after harvesting, and by that time, it will be too late to correct any faults, this is the worst case scenario. You may notice white mold forming on your leaves, which prevents them from absorbing light and water. White mold will consume the nutrients from your plants and, if not caught in time, might leave your harvest ineffective.

In addition, too little humidity in the grow chamber is detrimental to plants:

  • Stasis in growth can occur if your plant is concerned about becoming dehydrated. This can result in the closure of the stomata, which means that the plants will be unable to take in much (if any) water. Deficits in nutrients- Plants love to take in water vapor through their leaves, but when there isn’t enough water in the air, your plants will have to receive their water from another source: their roots. It is inevitable that nutrients will follow your plants when they are thirsty and absorbing a lot of water into their roots. A high level of nutrient uptake is detrimental to your plants, and you may see nutrient burn on the ends of your leaves as a result.

Temperatures and Humidity Levels at Each Stage of Development Just like we discussed before, plants flourish in a variety of humidity levels throughout their lives at all stages of development. Consider the following as an example of where the humidity level in your grow room should be located: Seedlings/Clones: 70-75 percent of the population Humidity- Because your plants require time to establish strong root systems, the bulk of the water they receive is through their leaves. When your plants are newborns, you must ensure that there is sufficient moisture in the air to ensure that they are adequately fed.

  1. For vegging plants (up to flowering), maintain a humidity level of 50-70 percent in the grow room.
  2. Because plants will still need to absorb moisture via their leaves throughout the early phase of their vegging cycle, you’ll need to maintain relatively high humidity levels (60-70 percent) at this time.
  3. Humidity in a blooming plant’s growing environment: 40-50 percent of the population Humidity- Flowering plants require a suitable climate in which to grow, one that is neither too hot nor too cold.
  4. As you come closer to harvest, you’ll progressively reduce the temperature down to around 40 percent when you’re ready to clip, lowering it by 5 percent every 2-3 weeks until you reach the desired harvest temperature.
  5. You want to make sure that the environment isn’t too humid in order to avoid the development of mold.
  6. When harvesting, make sure your plants are in a location where the humidity levels are consistent and the temperature and heat are around room temperature and heat level.

Adding and removing humidity from your growing environment There are a handful of things you can do to change your humidity levels if you find yourself leaning toward being too damp or too dry while checking your humidity levels; There is too much humidity: If the air is overly humid, you may use a Dehumidifier to remove the extra moisture from the air.

Make careful to check to see when the humidifier is full and empty it if it doesn’t have a drainage mechanism, especially if the unit doesn’t have one.

Whether you just open a window or use a duct fan to drive the moisture out of the grow space and outside, it is important to do it often.

There isn’t enough humidity: Adding a humidifier to your grow space may significantly improve the humidity in your grow space.

This will allow you to know when to stop pumping the air full of moisture. Remember that humidity levels and temperature interact with one another, so raise the temperature when you want a humid atmosphere and lower the temperature when you want less moisture in the air to keep it humid in there.

How To Increase Humidity In Grow Tent? Easy With 5 Tips!

Are you a gardener who enjoys your work? A garden tent is a terrific alternative if you want to be able to plant all year round without interruption. Grow tents are beneficial to gardeners because they allow them to manage the growth environment. These tents are composed of stretchy fabrics and have a bright lining on the inside to keep you visible in low light. It contributes to the retention of heat within the tent. Unfortunately, keeping the proper humidity levels within the grow tent is not a straightforward task to accomplish.

  • In my grow tent, I couldn’t figure out how to raise the humidity level!
  • Plants might suffer from reduced growth and development as a result of low humidity.
  • At different periods of a plant’s life, however, the amount of humidity it requires might vary significantly.
  • Otherwise, you risk losing your plants to the environment.

Why Is Humidity Important?

Humidity may be defined as the amount of water vapor present in the air in a specific location at any given time. In order to grow tents, we must first determine the relative humidity. It informs you of the percentage of water that is present in the surrounding air as well as the maximum amount of water that may be present at a certain temperature. A hygrometer may be used to determine the humidity level. It would be great if you kept in mind that plants may thrive at a variety of relative humidity levels; nonetheless, the temperature within the grow tent will have an impact on how well they develop.

What Happens When Humidity Is Low?

Water is essential for plants, as we all know, but what about relative humidity? When the temperature is high and the amount of water available is limited, dry air is produced. The plants are under extreme stress as they attempt to absorb more moisture in order to counteract the drying impact of the roots. Lower humidity levels can cause the roots to absorb more water, and if there are nutrients in the water, this surplus water can be detrimental to the plant’s health and growth. Low humidity can also increase the likelihood of a plant becoming afflicted with mildew or being infested by other insects.

Why Is High Humidity Important?

I was apprehensive about excessive humidity at first, and I was even concerned that it would hurt my plants. However, via trial and error, I have discovered that a high degree of humidity is really beneficial, particularly during the developing period. Because of this, the plants are able to absorb as much water as they need to survive.

However, plants also absorb nutrients and water via the leaves and stems of the plants they consume water via. When there is a high level of humidity, plants have a better chance of receiving adequate water and growing properly.

What Are the Suitable Humidity Levels?

Natural humidity levels always fluctuate, therefore it is advisable to adjust the humidity levels in a grow tent in accordance with the various stages of a plant’s life cycle. For further information, please see the video below.

  • Seedlings and young saplings demand a higher level of humidity. Ideal percentages should be between 70% and 75% of the total population. This is the period of time during which the plant’s root system is developing. It is important to maintain high humidity levels in order for saplings to establish robust root systems. Flowering plants need relative humidity levels between 40 and 50 percent to thrive. It provides them with an atmosphere that is favourable to their growth. Mildew and mold development can also prevented by maintaining slightly lower humidity levels. Humidity levels between 50 and 70 percent are ideal for plants that have already established themselves in the ground. Despite the fact that their roots have already established, they continue to suck in moisture through their leaves in order to grow more quickly. If possible, keep the humidity levels between 45 and 50% while you’re harvesting your crops. As a result, the fruit and vegetables will not get brittle or dry.

Although it is important to understand that relative humidity affects humidity levels, it would be preferable if you kept this in mind. So, before raising or reducing humidity levels, spend some time learning about how humidity behaves and affects plant development.

How to Increase Humidity in Grow Tent?

There are a variety of approaches that you may use to deal with the humidity issue. It will be determined by your financial situation and the amount of effort you are prepared to put in. Modest gardeners can get by with a few small stages, while more expert gardeners and pricey plants may need to take a few more significant measures. I’ve outlined a few possible courses of action from which you might chose based on your own circumstances.

See also:  How Big Is A 10X10 Tent

1. No Cost and DIY Changes

  • Mixing mature plants with young ones is one of the simplest things you can do in your garden. Larger plants respire more deeply, which raises the humidity levels in the growth environment. In any case, avoid overcrowding the tent, since this will make it difficult for tiny plants to acquire enough light and nutrients. Remove a Couple of Lights- It’s a simple matter of logic. Increases in temperature are accompanied by a decrease in humidity. Fluorescent lights generate heat, which may be used to dry a tent. Remove a few lights from the tent, but make sure there is still enough light in the tent. Fan Speed- For plants to thrive, free airflow and appropriate ventilation are essential for healthy growth. The fans that you employ must be adjusted at a reasonable speed to be effective. If the pace is too high, it might cause the plants to dry out and also prevent vapor from settling on the leaves of the plants. The low speed will cause the humidity levels to rise. Towels and trays- This is a low-cost and simple approach for increasing humidity. A damp towel should be hung near the air intake. Placing trays of water near the plants or near the passive air holes will help to keep them hydrated. Wet sponges are also an excellent alternative. It is possible to position them near a plant and watch the water slowly evaporate
  • Spray Bottle- Spray bottles are commonly found in the gardens of most people. Use it to spray water on the tent’s walls twice a day, seven days a week. As a result, the water lingers on the surface for a longer period of time, providing the plants a better opportunity to absorb it.

2. More Expensive Changes

If none of the measures outlined above are successful for you, it is time to consider some alternative possibilities. The grow tent or space may be rather large, in which case these DIY techniques will be ineffective. You will have to spend some money, but believe me when I say that the results will be well worth your while.

  • Install an air conditioning unit- If you currently have an air conditioning unit in your grow tent, but it is not adequate, it is time to either replace it or add another unit. Before purchasing a new air conditioning unit, carefully analyze your needs depending on the weather, tent size, and other factors. Soil on the Floor- If your tent takes up a significant amount of space, it is likely that you will have some soil on the floor. You have the option of replacing this soil with one that has superior water retention. Alternatively, you may scatter it about the plants and observe the humidity levels rise
  • Construct or purchase a Propagator setup. Seedlings and young shoots are well protected when grown in a propagator, and the increased humidity aids in the growth of the plants. You will require the following items in order to construct your own set-up:

Allow the water to run into the humidifier through a pipe and see how it generates a cool mist in the tent as it does so.

  • Humidifier- If you don’t already have one, you should consider investing some money on a high-quality humidifier. It may be able to resolve all of your humidity issues. Maintain a working percentage of 50 to 65 percent. Get a humidifier that has an automatic control feature to make things even better. Keep an eye on the humidity levels, as too much can cause problems.

Humidifier Facts

When we talk about boosting humidity, the first thing that comes to mind is the use of a humidifier to accomplish this. It has the ability to boost the moisture content of any growing environment by releasing water vapor into the air. Nonetheless, humidifiers are essential to a plant’s existence, especially when the plant is kept in a tent. Humidifiers may increase relative humidity in a limited space, making the environment more favorable for plants. You can achieve the appropriate quantities of phosphorus depending on the plants and their growth stage.

  • As soon as we hear the words “increase humidity,” the first thing that springs to mind is “hygrostat.” Water vapor may be released into the air, increasing the moisture content of any grow area. When growing plants under a tent, humidifiers are very important since they keep the soil moist. Humidifiers can improve the environment for plants in limited spaces by increasing relative humidity. You can attain the appropriate levels based on the plants and their growth stage. Keep the following considerations in mind when purchasing a humidifier.

Can High Humidity Be Bad?

Having too much of a good thing may be detrimental, just as it is with everything in life. Even though high humidity is beneficial to plant growth, excessive humidity can do more harm than good if it becomes too prevalent. Extremely high humidity can result in a variety of difficulties, including

  • Molds are allowed to develop, and the plants’ ability to transpire effectively is hindered. It promotes the growth of bacteria and other undesirable organisms. The capacity of roots to absorb water diminishes, and they become more passive as a result. Reduce carbon dioxide intake, which is necessary for photosynthesis, by clogging the stomata of plants.


After reading this article, you should realize that increased levels of humidity in a grow tent are beneficial to the optimal growth of plants. It’s important to remember that humidity is affected by a variety of different elements, including ventilation, light, temperature, and water. As a result, it is a good idea to keep track of all parameters, not only humidity. When you have finished reading the information I have provided here, you will have a better understanding of how you may enhance the humidity levels within a tent.

The cost-effectiveness of some of the solutions allows you to experiment with them early in order to figure out what works and what doesn’t.

Please do not hesitate to contact us if you have any questions or concerns.

If you find the material beneficial, please forward it to anyone who may be in a similar situation. We are certain that you will soon be able to observe your plants developing more quickly and in a healthy manner if you follow the advice provided here.

How to Raise Humidity in a Grow Tent

Indoor gardeners are faced with a number of difficult challenges, one of which is how to maintain humidity in a grow tent or grow room. How to boost humidity in a grow tent and how to raise humidity in a grow room will be discussed in this post, as well as some solutions for keeping your plants from drying out will be discussed. It’s important to keep a few things in mind when you’re thinking about growing plants inside. This is especially true if you are growing in a limited location like as a grow tent or a grow chamber, as described above.

The use of grow tents allows you to care for a range of plants all year long and grow a variety of fruits, vegetables, and flowers regardless of the present weather or climatic zone.

A grow tent’s advantages include a more efficient absorption of nutrients by the plants as well as the prevention of potentially harmful elements found in soil, such as parasites, extra dirt, mold and mildew as well as the eggs or larvae of plant-eating insects, from establishing a home in the plants.

Or, to put it another way, the quantity of water vapor present in the air.

Importance of High Humidity

One of the reasons that humidity should be maintained at a somewhat high level is that plants require water in order to survive. While plants can obtain water through their roots, the fact is that they also obtain water through other organs of their bodies. In a more particular sense, they also absorb water from their stomata by way of the water vapor in the surrounding environment. Unless there is a significant amount of humidity in the surrounding environment, they will not be able to obtain enough water for growth and development.

Consequences of Low Humidity

The growth of young plants is badly affected when they are not exposed to high amounts of humidity. Low moisture compels the plant to perform more effort, which may reduce its life or cause it to grow and develop more slowly or even hinder its growth and development. Aside from desiccation, other implications of low humidity in the growing environment include the development of mold and mildew on the plant, as well as the infestation of insects such as spider mites on the plant’s leaves.

It is believed that plants that are much less wet are more desirable and conducive for other creatures to take advantage of and thrive on, which accounts for their fragility.

How Measure Humidity in a Grow Tent

In order to accurately measure the relative humidity in a grow tent, either a hygrometer or a device with a humidistat will be necessary. Hygrometers are used to monitor and control humidity levels in a place; humidistats, on the other hand, are devices that are incorporated inside devices to assist in regulating humidity levels in a room. To put it another way, a humidistat will include a built-in hygrometer that it will utilize to measure the humidity so that it may take appropriate action.

First and foremost, if you just want to know the relative humidity in your grow tent at a glance, you should investigate hygrometers.

For those of us who want to keep track of how the humidity changes over time, I’d recommend something like the Govee Temperature Humidity Monitor, which is available on Amazon.

Being aware of how temperature and humidity fluctuate might assist you in determining what changes you should make to the configuration of your grow tent.

How to Increase Humidity in a Grow Tent

Grow tent fans are essential because they allow air to flow and be evenly distributed among plants, which is essential for successful cultivation. This makes it easier to interchange air between the interior of the grow tent and the outside, which is important since fresh air must be provided to prevent hazardous germs from rising in quantity and/or remaining in the growing environment. (For more information on fans, see my page on grow tent setup.) However, if you have your fan speed set too high, the air will dry out more quickly, rather than allowing the water vapor to settle and be absorbed by the plants in your vicinity.

Add a Humidifer for Grow Tent

If you want to actively regulate the humidity in your grow tent, you should consider installing a humidifier or dehumidifier in your grow tent. When selecting a humidifier, take into consideration the amount of space available in your tent or room. If you’re looking for a small to medium-sized tent, consider the following options: Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier Because of its small size, low power consumption, and adjustable nozzle, the Pure Enrichment MistAire Ultrasonic Cool Mist Humidifier may be easily integrated into almost any grow tent environment.

It does not have a built-in humidistat, which is the only function it lacks.

Set the humidistat to the desired humidity level (within +/- 5 percent), and it will turn itself off once the desired humidity level is reached.

This is a fantastic feature at an extremely reasonable price. Keep in mind that, regardless of the humidifier you use, you should aim to maintain a humidity level of at least 60% for your younger plants.

Lower the Temperature of Surroundings

It is well known that chilly air will always sink to the bottom of a container due to the relative density of the air. A lower temperature indicates that the air is comparatively moist, resulting in a greater concentration of water vapor in the atmosphere. Increasing the temperature of the heater or decreasing the temperature of the air-conditioning system, either in the tent itself or in the grow room, is all that is required to achieve this result. An other method for you to accomplish this would be to reduce the intensity of the UV light, which is beneficial since it promotes the evaporation of water.

Have Larger Plants inside the Grow Tent as Well

While some people believe that larger plants will deprive the younger plants of air, the reality is that when larger plants are placed inside a grow tent with the baby plants, they actually contribute to the level of water vapor and, as a result, the humidity inside the grow tent once the baby plants are removed. Just make sure that you don’t overcrowd your grow tent with plants. Large plants, too, are subjected to the respiration process, which results in the emission of carbon monoxide and water vapor into the atmosphere.

This vapor then provides nourishment for the younger, smaller plants.

Place Water Sources Wherever Possible

When it comes to raising humidity in a grow tent, one of the most obvious and straightforward methods is to arrange water trays near the air intake tubing or passive air openings. You can also soak sponges and place them near your growing trays to aid in drainage. The heat emitted by the grow lights or heater will gradually evaporate this water, increasing the humidity within the grow tent in the process.

Cover Young Plants With Clear Glass or Plastic

Cover immature plants with a plastic tray cover or even plastic wrap to provide them with their own micro-climate within the grow tent, using a gentle touch. This enables them to collect and maintain their own moisture for a longer period of time while still allowing them access to light and ventilation. If your plants are a little larger, you might want to consider other clear solutions, such as bell cloches.


The necessity of keeping things wet inside your grow tent or grow room cannot be overstated; yet, one of the most important considerations is that the water you use should be as clean as possible. The presence of harmful bacteria can result in a variety of ailments in your plants as well as in you. Regular maintenance, apart from just maintaining the humidity in the grow tent, should be considered a vital part of the process of growing your plants. Furthermore, while placing sponges or small pans of water near fans, use caution since they are electrically charged objects that may short circuit if they come into touch with water.

Thank you for reading this and I hope it has answered your questions regarding how to boost humidity in your grow room or grow tent. Have you enjoyed this post? Make a note of it and pin it!

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