How To Increase Rh In Grow Tent

12 Ideas On How To Increase Humidity In Grow Tent

Have you noticed that your plants are pleading for water? Have you noticed that the leaves on your plant are curling upwards? Learn how to boost humidity in your grow tent or grow room if the air in your grow space is becoming too dry. Every indoor grower is aware that maintaining proper temperature and humidity levels is essential to providing your plants with a favorable environment in which to thrive. Knowledge of how to manage and enhance relative humidity in a grow tent is something that all indoor gardeners should be familiar with.

However, if your grow tent is just 20 percent to 40 percent full, you must take action immediately or risk losing your plants completely.

Low humidity within a grow tent causes your plant’s growth to be hindered and its development to be poor.

This is why increasing the humidity in a grow tent is necessary.

The strategies I’ve attempted to enhance humidity in a grow tent or grow room over the years are discussed in detail in this post, which will be a cost-effective exploration of the approaches I’ve tried.

Humidity Basics

The amount of water vapor trapped in the air is referred to as humidity. Humidity may be measured in three ways: in absolute terms, in relative terms, and in particular terms. You may also use a hygrometer to determine the humidity level, which should be one of your gardening closest friends. Because we are interested in indoor gardening, we pay particular attention to relative humidity. The relative humidity (RH) of the air is measured in relation to the maximum quantity of water that may be kept in the air at a given temperature.

It’s important to remember that the warmer the air, the more water vapor it may contain.

Consequences of Low Humidity in a Grow Tent

Now it’s time to go over some broad science! Water is used by plants to keep them cool. Their roots, which are connected to the plant’s vascular structure, absorb a lot of water, with around 95 percent of it flowing to the roots and subsequently escaping through the stomata. Only roughly 5% of the budget is allocated to the creation of additional cells. As a result of the high temperatures and dry air, there is a significant vapor pressure deficit between the leaves of your plants and the surrounding environment.

As a result, your plants are exposed to the dry conditions of the outside environment.

Growing plants become stressed as a result of the additional pressure they place on their roots in order to suck up water and compensate for a lack of humidity.

Lower levels of humidity encourage the roots to take in excessive amounts of water, which contains surplus nutrients that can burn the tips of the leaves when they are exposed to direct sunlight.

Due to a lack of humidity, there is also the danger of plant desiccation, which results in the plant becoming vulnerable to infestation by insects such as molds, white powdery mildew, and spider mites.

Importance of High Humidity in a Grow Tent

High humidity may appear to be a daunting prospect for inexperienced gardeners. Take it from a group of seasoned indoor gardeners. As grow tent users, we’ve seen firsthand how high humidity levels, particularly during the growth period, may be really advantageous. Basically, exposing your developing plants to relatively high humidity aids in the absorption of water by the plants, which is essential for their survival. Plants absorb water through their roots, but they may also be able to obtain additional water through their leaves and stems.

If there is little to no humidity, plants will not have the opportunity to get enough water for their full development and growth.

Things to Review

Keep in mind that relative humidity should not be lower than 20 percent and must not be more than 75 percent. If you have a 44 grow tent, you will most likely need to maintain at least 40% humidity, however a 55 grow tent may require as much as 65 percent humidity to thrive.

The Best Temperatures for an Indoor Grow Room or grow tent

As I previously stated, the ideal grow tent temperature changes depending on the period of plant life in which it is used. Temperature and humidity go hand in hand in a grow tent. It is natural for indoor gardeners to invest in a digital thermometer and hygrometer to assist them keep track of readings.

  • Clones or seedlings like temperatures between 74 and 78 degrees Fahrenheit
  • Vegetable plants prefer temperatures between 70 and 78 degrees Fahrenheit
  • And flowering plants prefer temperatures between 88 and 75 degrees Fahrenheit. The harvesting process usually necessitates temperatures between 65 and 74 degrees Fahrenheit.

What Is The Right Humidity Level?

Plants require varied degrees of humidity at different times of their lives, just as they do at different temperatures.

  • When clones or seedlings are growing, they require 70 percent to 75 percent humidity since this is the time when their root systems are developing. You may do this by utilizing propagation trays or humidity domes to provide enough of moisture in the air for your young plants to grow in. Maintaining high amounts of humidity will enhance the likelihood of your clones successfully rooting
  • Vegetable plants require 50 percent to 70 percent humidity since their roots have already begun to grow. They do, however, require the assistance of leaves in order to absorb moisture. Low humidity levels might cause development to be more sluggish. For flowering plants to grow in a pleasant atmosphere, they require 40 percent to 50 percent humidity on a consistent basis. It is possible to prevent mildews or molds from growing at this period by keeping a significantly lower humidity level
  • Humidity levels of 45 to 50 percent are normally required while harvesting in a grow tent in order to avoid your crop becoming harsh and brittle.

How Grow Tents and Relative Humidity Can Help You Grow Plants

The use of a grow tent in conjunction with a climate controller allows you to exert greater control over your plant’s growth environment. Not to mention that it will assist you in controlling the lighting cycles. Furthermore, in a grow tent with a modest air volume, it is easy to raise or increase relative humidity levels. A grow tent enables you to care for a variety of plant species throughout the year, regardless of the season, weather conditions, or climatic zone in which you are located.

Your grow tent will assist you in keeping potentially dangerous factors such as insects, mildew, mold, and parasites from causing harm to your plants and stopping them from growing.

This is why you should be familiar with the many methods of increasing the relative humidity in your grow room or grow tent.

12 Easy Ways on How to Increase Humidity in Grow Tent

It is a widely held belief that bigger plants would suffocate smaller ones by consuming their light, nutrients, and oxygen. On the contrary, as you begin to add plants to a grow tent, especially large ones, the relative humidity will rise as a result of the increased respiration and production of relative humidity. Carbon dioxide and water vapor are released by your larger plants during their respiration, which helps them to nourish their smaller ones. Larger plants have larger leaves and more stomata, which means they may expel more water vapor following evapotranspiration than smaller plants.

Your developing plants will subsequently be able to utilize this water vapor. The goal is to avoid overcrowding the larger plants in order to guarantee that all of your growing plants receive an equal amount of air, light, and nutrients.

2. Use a Humidifier inside grow room

Investing in a humidifier has proven to be one of the finest decisions I’ve ever made. A humidifier helps to maintain high humidity levels in a grow tent by extracting a cold mist, which is essential for the development of your growing plants as they expand. Increase the moisture level of your humidifier to at least 50 percent to 65 percent, depending on the size of your grow tent. The humidifier should be placed on the bottom level of your grow tent if your grow tent has a top and bottom shelf.

However, I must caution you that leaving your humidifier running at maximum capacity in a restricted place may result in an excessive amount of moisture in the air.

I strongly advise purchasing a humidifier that has the capacity to hold at least six gallons of water at a time and has a lengthy operating life span.

3. Make Use of Propagators

Seedlings can germinate on their own in certain cases, but increasing the humidity in your grow tent with propagators can increase the likelihood of success in your plant growing endeavors significantly. Keep an eye out for how indoor gardeners safeguard their seedlings and cuttings in propagation trays and containers. Preventing the seeds from drying out can be accomplished by using propagators such as this covered propagator with a polyethylene or glass cover sheet. They have the ability to maintain high humidity levels in your grow tent, guaranteeing that your seedlings’ root systems are not stressed during the development and growth process.

4. Build your own propagation set-up

Here’s an example of an experiment that was successful for me. An adjustable extractor with a built-in thermostat that regulates the temperature by sucking in the air has been purchased for my home. I then poured a pail of water on top of my grow tent to keep it from drying out. A hosepipe is used to transfer the water into the humidifier. Suitable for both seedlings and cuttings, this procedure is simple and effective. Because it extracts a cool-mist from within the grow tent, the humidifier will help to increase relative humidity in the growing environment.

5. Hang a wet towel or set trays of water near passive air holes

Hanging a wet towel or putting a pan of water near air intakes is an apparent solution that will mist your walls and enhance the humidity level in your home. This enables for a significant amount of moisture to be absorbed into the air as a result. A towel, on the other hand, has a tendency to dry quickly and will require you to rewet it from time to time. In addition, a pot or pan of water will not necessarily produce the required relative humidity level for your environment.

6. Remove Half of Your Fluorescent Lights

Unfortunately, the most obvious answers are often the ones that are neglected. By deleting half of your fluorescent bulbs, you can lower the temperature in your home. Don’t be concerned about the strength of the light because your tiny plants don’t require much light at this point. Ventilating a grow tent is essential since it may assist you in managing or controlling the relative humidity of your plants’ environment. A properly ventilated grow tent ensures that air is exchanged both in and out of the tent during the growing process.

You can prevent hazardous germs such as fungus and bacteria from growing or surviving inside your tent as a consequence of sufficient air circulation in your tent.

Using high-speed fans will cause the air to dry up more quickly than usual, so proceed with caution.

Consequently, moisture is kept away from the plants, which can prevent dehydration and desiccation from occurring in the plant.

You may also experiment with lowering the number of fans in your grow tent in order to boost the humidity level. I recommend that you set the fans to 60% of their maximum power in order to maintain relative humidity.

8. Make use of water spray bottle

Growers are often equipped with spray bottles, so this should not pose an issue. Another simple approach is to spray water on the walls of your grow tent every morning and evening, which will keep your plants healthy.

9. Lower the surrounding temperature

Even while learning how to chill a grow tent in order to boost water vapor is common knowledge among indoor gardeners, it may be difficult when temperature management is required. Keep in mind that because cold air has a higher density than hot air, it will sink to the bottom of the container. Generally speaking, a lower temperature indicates that the air is relatively moist and contains a significant amount of water vapor. In a similar vein, decreasing the intensity of UV light can aid in the production of water vapor, but only if the amount of light is sufficient to enable water evaporation.

10. Opt for a swamp cooler

I use a swamp cooler to help keep the temperature in my grow tent down on occasion. The gadget assists in both cooling the air and increasing the humidity levels at the same time. It is capable of operating when the humidity is exceedingly low and the temperature is exceptionally high.

11. Stock up on water sources in your grow tent

Another low-cost method of increasing humidity in a grow tent is to increase your water supplies and distribute them more evenly around the tent. Water trays are often placed near to air intake tubes or passive air openings in my home. Similar to this, placing wet sponges near to growth trays is effective. As a result of the heat generated by a grow light or an air conditioning system, the water in the sponges will gradually evaporate, increasing the humidity in your grow tent. A pleasant reminder to utilize clean water in order to prevent unwanted fungus or bacteria from accumulating in your growing environment.

Fans and grow bulbs are powered by electricity, and when they come into touch with water, they may short circuit.

12. Reduce temperatures by adding an air conditioner to your tent

Gardeners may get high humidity in their grow tents by increasing the temperature of their air conditioners or decreasing the temperature of their heaters. It might be expensive, but it’s another option to consider if you’ve exhausted all other possibilities.


After everything is said and done, maintaining high humidity levels in your grow tent is critical to the development and health of your plants. Keep in mind that managing humidity necessitates taking into account other variables of indoor horticulture, such as temperature, ventilation, and lighting. All of the solutions I’ve discussed above are cost-effective, and the only decision you have to make is which is more appropriate for the circumstances of your grow tent and your budget. You may purchase a humidifier or air conditioner, but you can simply utilize ordinary household items to get the same results.

As a result, you may need to experiment with different methods of raising humidity in an agricultural tent.

Originally from Arizona, Lindsey Hyland attended the University of Arizona’s Controlled Environment Agriculture Center, where she received her bachelor’s degree.

She created in order to share gardening advice and strategies with others. If you have questions about succulents and houseplants, veggies and herbs, or just about anything in a backyard garden or hydroponics garden, she’s delighted to help you out!

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

Do you have a marijuana plant growing in your home? Then you’ll have a significant edge. When you’re inside, you have total control over the surroundings. You have the ability to provide your plants with the optimal circumstances for maximum development and productivity. For plants, the optimal degree of humidity depends on the stage of development they are in. Of course, if the relative humidity within your grow tent falls outside of these optimal parameters, cannabis will continue to thrive.

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Furthermore, if the humidity is really low, they will suffer greatly.

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.

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 they aren’t already too enormous, they will be in the near future.

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).

Tap water will leave mineral deposits on the leaves of your plants, as well as on the walls and floor of your tent, if you use it to water them.

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.

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.

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

Extremely dry air can cause a variety of major health concerns. However, you must be careful not to raise the humidity levels too. When it comes to growing plants, too much humidity can be detrimental, especially during the blossoming period.

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.

An oscillating fan is ideal for this application.

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 Grow Tent (Instant Results Today)

(Discover 8 Relative Humidity Hacks to Boost RH Right Now) (Learn More About RH Today) Understanding how to boost humidity in a grow tent is critical for the successful development of cannabis plants. We have put our team of cannabis specialists through their paces testing grow tents in a variety of environments. In this post, we will share with you all of the hacks and tactics that we used to enhance humidity in our grow tents and grow rooms. It is possible to observe that the leaves are excessively dry, curled, or that nutritional burn has occurred if you are suffering with low humidity cannabis.

Continue reading for strategies and tactics that you can do immediately to improve humidity in your grow room or tent.

To jump to the portion of the article that is most relevant to you, please click on the link below.

  • Aid in the absorption of nutrients by plants through their leaves. It is important to avoid the drying and burning of cannabis plant leaves, as well as the overworking of nutrition draw through roots. The humidity levels fluctuate between the phases of juvenile and mature plants.

We put a variety of grow tents through their paces under realistic growth circumstances. In a standard-sized room, we put a 4 by 4 grow tent to the test. We also tried a 4 x 8 grow tent in a bigger space, and a 10 x 10 grow tent in a garage with A/C split support was also tested in this setting. We experimented with the following strains: Wookies, Peanutbutter Runtz, Thin Mints, and Gelato Cookies. Results: Our testing included using the sea of green approach in the smaller grow tents and the automated way in the bigger grow tent.

  1. If you are new to the horticulture industry, we recommend that you begin by studying how relative humidity (RH) works in a grow tent and why it is important to have a solid grasp of grow tent humidity.
  2. We used the same strains for all of our tests.
  3. Two of the grow tents (4X4 and 4X8) were tested inside the home, which was kept at 70/69 degrees Fahrenheit, and the 10 X 10 grow tent was supported by a mini-split air conditioner to keep up with the high temperatures of the California summer.
  4. There are several elements that influence relative humidity, however attempting to obtain the ideal RH may be accomplished in a variety of methods that are unique to each individual.
  5. Given that there is no one correct way to accomplish this, after we have provided you with all of the techniques, it will be your responsibility to try each one until you obtain the RH levels you desire in your grow tent.

What is Relative Humidity in Grow Tent?

Temperature = (Vapour Density /Saturation Vapour Density) X 100 percent Relative humidity is measured in percentages, and the higher the percentage of relative humidity in your grow tent, the greater the amount of water vapors that are soaking the air. This is why humidity in the air has a tendency to seem “thick.” When you unzip your grow tent and peek your head inside, you will immediately notice that the relative humidity is quite high. During our research with grow tents, we discovered that after a month or two, you can memorize the relative humidity levels just by feeling the air.

How Raising Humidity in Grow Tent Helps Cannabis Plant Growth

The relative humidity is expressed as a percentage. When relative humidity (RH) values hit 100 percent, the air is unable to store any more moisture, and mist, fog, or even rain may emerge as a result. In addition to absorbing moisture via their leaves, cannabis plants take in water through their roots. The importance of measuring relative humidity cannot be overstated because if the humidity in your grow tent is too low, the plants will be forced to receive all of their nutrients through their roots.

Nute burns will develop as a result of this, as will a reduction in the potential growth of trichomes and the density of buds. Return to the top of the page

How to Measure Humidity Levels

When determining relative humidity, it is advisable to use a hygrometer. A good option would be a hygrometer that has a temperature setting as well as phone notifications to tell you when relative humidity (RH) is dangerously low. We propose theGovvee Bluetooth Hygrometer since it is cost-effective and lets you to follow your procedure using an app on your smartphone. You should only use one or two humidity growth techniques at a time, so that you can observe how well they work before moving on to another.

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Optimal RH Levels for all Plant Stages

ClonesSeedlings Weeks 1 and 2 Vegatative Weeks 2 and 3 Vegatative Flowering that occurs early Harvesting near the end of the flowering season Depending on the stage of development you are in, you will need to adhere to the humidity standards shown below in your grow tent. Most novices will find it difficult to cope with increased humidity levels throughout the clone/seedling and early vegetative stages of their plants. The reason for this is that the plants are considerably smaller in size, and the vapor created by the smaller plants is insufficient.

As the plants develop and/or as you add additional plants to your grow room, you will find yourself having difficulty keeping the humidity levels stable.

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Increase Humidity in Grow Tent (Beginner Friendly)

Raising the humidity in grow tent setups isn’t a difficult feat to do. Keep in mind that everything is relevant to your specific growing environment. Are you utilizing a 10 X 10 grow tent, or perhaps a 4 X 2 grow tent for your cannabis cultivation? The greater the size of your grow tent or grow room, and the fewer plants you have (or smaller plants such as clones, seedlings, or baby veg stage), the more difficult it will be to raise the humidity in your grow tent or grow room. Keep in mind that plants create vapor as a part of their natural respiratory system.

This is a typical problem for beginners, but if you experiment with a few of the tips and tactics listed below, you can rapidly learn how to boost humidity in grow tent setups like a master in no time.

Adjusting Fan Speed for Optimal Grow Tent Humidity

Our first hack is what we call a “foundational” hack since it is so important. This one method will not be enough to get the ideal relative humidity, but it is critical that you get it correctly since it will help set you up for effective humidity levels throughout your cycle. One of the most fundamental foundations of humidity control is the adjustment of your fan. The reason for this is because most people have their fans set to the highest setting and, in many cases, aimed straight at their plants.

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The presence of moisture on cannabis plants in their early stages is critical for good plant growth.

Action-Item: What you’ll want to do is set your fan at a much lower speed and direct it toward the mylar wall of your tent or the tent’s roof, if possible. As a result, air is circulated throughout the tent while moisture is retained on the plant leaves. Jump Return to the top of the page

Temperature Change for Cannabis Low Humidity Issues

Dropping the temperature can also assist in raising the humidity levels in the air. It is usual for most individuals who acquire a grow tent to not consider the possibility of including an air conditioner in the mix. Our 10 X 10 grow tent was equipped with air conditioning, but we did not provide any further assistance for A/C in the 4 X 4 and 4 X 8 grow tents during our testing. Try to set your tent in a cooler room and position the a/c vent such that it is immediately above the roof of your tent.

Our normal house temperature is 74 degrees, but we ran the A/C at 70 degrees, which helped significantly in cooling down the tent and resolving our RH issues with our clones.

This is exactly what we did for our larger 4 X 8 tent, and it worked out well.

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The Infamous Wet Towel Hack for Low Humidity in Grow Room

A long time has passed since the damp towel tip for boosting humidity in a grow room or tent was first introduced. The higher the relative humidity (RH) in your tent, the more moisture there is. Now, keep in mind that as your plants grow larger, the relative humidity will naturally rise; this is merely a temporary solution for when the plant size ratio in relation to the size of the space is not balanced. Grow tents are constructed with metal framing, which allows you to wet a towel and hang it in the interior of the tent together with the metal framing.

The combination of hanging two damp towels in our 4 X 4 grow tent, as well as the temperature decrease and the fan hack, was more than enough to produce excellent results.

Continue reading below.

Water Tray or Water Spray for Low Humidity Cannabis

It’s no surprise that this is my favorite trick for boosting humidity because it’s the same hack that million-dollar grow companies employ. I’ve had the opportunity to work with some of the greatest growers in the business and was given the opportunity to visit some of the most successful grow operations, some of which had over 4,000 plants. When it comes to huge grow rooms as well as grow tents, humidity is a major issue. A typical method warehouses employ is to leave the reservoir in the veg room if they want to make a room more humid.

As flowering progresses in the warehouse flower room, the reservoir is located outside, where it can reduce humidity.

In addition, I enjoy getting a water spray, and I spray the walls and floor of the grow tent inside three times a day to bring more moisture to the environment.

In the event that you mistakenly pour nutrients into the spray bottle and they drop on the leaves when the lights are turned on, this can result in burns.

In the case of a larger grow tent or room, or if the temperatures are simply too high, you will want more advanced ways of cultivation. Continue reading to learn about further solutions. Jump Return to the top of the page

How to Increase Humidity in Grow Room (Advanced)

Using more sophisticated methods may be necessary if you are growing in a much bigger space, such as an 8 X 8 grow tent or a 10 X 10 grow tent, or even in a full grow room. A huge grow room full of extremely little to little plants will make rising humidity levels a difficult task to accomplish successfully. If you have a few additional bucks to spend, we propose that you try one of the options listed below. Just a word of caution: most of these solutions are stand-alone solutions, which means you will not need to stack any of these approaches together unless you are experiencing extremely low humidity levels.

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How to Raise Humidity in Grow Tent: Supported A/C

If installing a ducting system from your house A/C into your tent isn’t adequate, we propose purchasing a supported A/C system to keep you comfortable. You may purchase an air conditioning unit and install it outside the grow tent, with ducting leading into the tent. If you have a larger grow tent or grow room and have not yet filled the entire tent with plants, you may install the air conditioning unit inside the grow room. Adjust the A/C settings until the desired relative humidity values are attained.

If your business is tiny, you won’t need a huge humidifier; a little one that can fit within your grow tent will suffice.

A typical error is to leave your humidifier running at full blast and then forget about it, only to return and discover that the relative humidity has soared to dangerous levels.

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How to Raise Humidity in Grow Tent: Plant Vapor

“Water is produced by plants in their respiratory system in the form of vapor. Find plants that are friendly with cannabis and purchase a couple to place in your tent to naturally enhance the relative humidity.” Plants emit vapor as a component of their respiratory system to help them breathe. When a result, as plants grow in size later in the vegetative stage, the relative humidity (RH) naturally rises. If you don’t have enough plants in your grow tent or if the plants are too tiny, you will have difficulty maintaining proper RH levels.

If you purchased seeds and do not have access to a nursery where you may get clones or mid-adult cannabis plants, this may appear to be an impossibility.

Just a few more plants will make a significant difference in the amount of vapor produced in your grow tent, and they won’t set you back an arm and a leg. Jump Return to the top of the page

How to Add Humidity to Grow Room: Misting System

There are a variety of misting systems available for purchasing, ranging from gardening to terrariums for reptiles, all of which are reasonably priced. A misting system is a fantastic technique to ensure a consistent stream of natural moisture is delivered to your grow tent or grow room on a consistent basis. As with the humidifier, you should start with the lowest setting and test with your hygrometer connected to your phone, keeping an eye on the relative humidity at all times. A misting system is a quick and easy way to raise relative humidity, but too much humidity is harmful to your plants.

Why Trust Our Research on Grow Tent Humidity Control

As your grow tent specialist, I have more than ten years of expertise in the cannabis cultivation industry. Previously, I worked with some of the top 20 cannabis farmers in the United States, and I was a part of some of the most successful grow operations in the state of California. Raising humidity in grow tent setups is something I’ve dealt with on a number of occasions in a variety of circumstances ranging from grow tents to grow rooms to warehouse manufacturing. I’ve worked with DWC, RWDC, SOG, and a variety of other hydroponic and aquaponic grow techniques throughout the years.

The only way to learn how to raise humidity in a grow tent is by trial and error, and all of the information provided comes from years of trial and error.

Best of luck with your growth.

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.

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. The good news is that you can easily enhance humidity in grow tents by employing a few easy techniques that require little effort.

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.

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, since too much might cause difficulties.

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.

  • The area to be covered by the grow tent, as well as its size, are critical considerations. Choose a humidifier that has the capability of covering the entire space. It also depends on the rate at which it humidifies and how long it may be left running. Look for a company that provides extensive and consistent coverage. The Water Tank’s Capacity- Every humidifier comes with a water tank of varying sizes. It would be better if you gave it some serious thought before proceeding. If it is too little, you will have to replenish it on a regular basis. When it is too large, finding a suitable location for it might be difficult. It is important to check if the humidifier has many settings available since you may require different mist settings at various times of the day. Safety features are quite important for any electrical item, and this is especially true for a humidifier. Some have an automatic shut-off feature that kicks in as soon as a specified humidity level is achieved
  • Others have a manual shut-off feature.

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.

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.

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