How To Raise Rh 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. It works well on seedlings and cuttings that won’t be able to absorb water through 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.

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(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.

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.

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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.

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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. Jump Return to the top of the page

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.

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

As a result, air is circulated throughout the tent while moisture is retained on the plant leaves.

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.

Using all of the above, as well as my personal favorite hack, will be necessary if you are dealing with a larger grow tent or attempting to enhance humidity in a grow room. Continue reading below. Jump Return to the top of the page

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.

  1. As flowering progresses in the warehouse flower room, the reservoir is located outside, where it can reduce humidity.
  2. 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.
  3. 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.
  4. 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.
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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.

You will need to replace the humidifier in your grow tent on a regular basis, but as previously said, you will only have difficulty boosting the relative humidity (RH) during the early phases of growth. Return to the top of the page

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.

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 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. 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.

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.

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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 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.

The purpose of this article is to explain how and why moisture plays such an important part in the growth of plants, as well as how to improve humidity levels in a grow tent if the levels are determined to be too low in the first place.

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.

Raising humidity in a grow tent may be accomplished by turning down the fan speed or using a timer to regulate how often the fan operates.

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: MistAire Ultrasonic Cool Mist Humidifier with Pure Enrichment Technology 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.

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 may also soak sponges and place them near your growth trays to aid with 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.

Have you enjoyed this post?

5 Easy Ways to Raise Grow-Room Humidity

It is impossible to overstate the importance of managing the environment in a grow room. This is true for every indoor garden, from the smallest garage operation to the largest warehouse business. We’ll presume you’ve made the necessary investments in lighting, ventilation, dehumidifiers, and air conditioning equipment since no one in their right mind would get into flower production with the intention of growing low-quality blooms. However, what gets lost in the shuffle from time to time is a method of introducing humidity into a place in a regulated manner.

See also:  How To Put Up An Ez Up Tent By Yourself

This is most prevalent in young seedlings, although it can also occur in more older plants in severe circumstances, and it is more common in young seedlings.

The Root of the Problem

The majority of the time, RH issues occur in young plants and seedlings that have undeveloped roots. This is due to the fact that the plant cannot yet absorb enough water to sustain itself, and as a result, the majority of its water intake comes through the leaves. It is possible to have leaves curl upward like small spoons if the humidity levels are too low. Alternatively, if the roots are a little more established, low RH can cause the young plant to drink excessively, which will frequently result in “nutrient burn,” which is characterized by brown tips on your leaves.

This is why some gardeners choose to start their seedlings in propagators rather than directly in the ground.

Relative Humidity Explained

In the simplest terms conceivable, relative humidity (RH) is the quantity of water vapor that is possible in the air at a certain temperature – represented as a percentage of that temperature. The higher the temperature, the greater the amount of vapor that can be held. As a result, it comes to reason that the lower the temperature, the less it is capable of holding. Understanding this is critical to understanding how to deal with relative humidity in your growing environment. Temperature and relative humidity have a yin yang relationship in that raising or lowering the temperature has the opposite impact on the relative humidity.

We can enhance RH in one of the following methods, now that we know what we’re talking about: A) Increase the quantity of water vapor in the air without altering the temperature, or B) Decrease the temperature without impacting the amount of water vapor already present.

Dealing with Low RH

In the meanwhile, as promised, here’s a fast and dirty breakdown of five simple solutions for dealing with low relative humidity in your room. Reduce the temperature of the room. Due to the fact that it is critical to the operation of RH, it is almost unjust to include it. As an added benefit, make certain that your grow chamber is well sealed and insulated from the outside environment in order to eliminate even the slightest external effect on temperature, as temperature and relative humidity are inextricably linked.

  • It is possible that introducing water vapor will be a more effective alternative in the event that the temperatures in the room are comfortable.
  • This can come in handy when you’re in a bind.
  • In order to boost the efficacy of this method even further, place a sponge in the bowl or trays to increase surface area, which will cause vapor to be released into the air even faster.
  • Growing plants perspire at a higher rate than seedlings, which raises the relative humidity (RH) in the space.
  • Introduce a Humidifier into your home!
  • When using any of the above choices, the addition of humidity or the reduction of temperature results in an approximation of the relative humidity value rather than a precise quantity of humidity.

All of this was just a long-winded way of stating, “Use the proper tool for the task.” In the meanwhile, if you’re experiencing difficulties with low relative humidity, maybe this article has helped you understand the root causes of the problem and provided you with some temporary solutions until you can make the investment in humidifiers.

Happy growing, and as usual, thank you for visiting. ControlYourGrowTopics: Humidifiers, as well as the setup of a grow room

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.

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.

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