How Humid Should My Grow Tent Be

Humidity: Finding the Sweet Spot for Your Grow Room

This is fantastic since it indicates that your plants are breathing properly and that there is no lack of water throughout your grow room orgrow tentseasily. Different degrees of humidity are required at different phases of a plant’s existence in order for it to seed, veg, and blossom in the proper manner. That said, you shouldn’t have a humidity level in your grow room higher than 70% at any time, so if you’re approaching that level, you might want to think about where the moisture is coming from and what you can do to avoid it from damaging your grow.

Where’s all that grow room humidity coming from?

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

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

The carbon dioxide (CO2) that plants naturally emit can raise the temperature of the grow room, which will result in moisture accumulation, which will boost the humidity. If you utilize CO2 in your grow, the humidity level in your grow room will climb even more. Grow equipment, including as grow lights, can also contribute to the increase in temperature in your grow space. When the temperature in your grow room is high and the lights are turned off, the temperature will drop. After a significant drop in temperature, you may see moisture accumulating around your lights, which is a symptom of relative humidity variation.

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

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

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

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

  • Also detrimental to plant health is too little humidity in the grow chamber.

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

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

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

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

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

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

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

Marijuana Grow Room Setup: Optimal Humidity and Temperature

Despite the fact that it is exhilarating to see the benefits of your effort when you begin harvesting, the task is far from finished. Preventing the possibility of your crop getting destroyed or rendered unusable for smoking by properly processing it is important. Proper drying and curing are critical in reducing the possibility of mold infection while also significantly improving the taste of the product when it is smoked.


Beyond the requirement for precise temperature and humidity management during the growth phase, it is also crucial to note that the humidity level maintained during the drying process is critical to the quality of finished product. If you have too much humidity in your drying environment, you may end up with perfectly cultivated cannabis that is moldy. That is something that neither the individual user nor the dispensary purchaser desires. Having moldy cannabis on your hands is one of the most effective ways to tarnish your reputation as a dependable grower of high-quality buds.

Wet Trimming versus Dry Trimming

Beyond the requirement for precise temperature and humidity management during the growth phase, it is also vital to note that the humidity level maintained during the drying process is equally important to the quality of finished product. A high level of humidity in your drying environment might result in moldy cannabis that is otherwise nicely cultivated. Everyone, both the individual user and the dispensary buyer, does not wish this to happen. Making your image as a reputable grower of high-quality buds tarnish with mold is one of the most efficient ways to destroy your business.

Wet Trimming

In addition to the requirement for precise temperature and humidity management during the growth phase, it is crucial to note that the humidity level maintained during the drying process is equally important to the quality of the final product. A high level of humidity in your drying environment might result in nicely cultivated cannabis that is moldy. That is something neither the individual user nor the dispensary buyer desires. Having moldy cannabis on your hands is one of the most effective ways to tarnish your reputation as a dependable producer of high-quality buds.

Dry Trimming

This approach is typically used by farmers who have a big volume of plant material and little time to handle it. The process entails chopping off branches and hanging them whole on drying lines to dry. Once the plants have dried, they are trimmed and prepared for processing.

The neatness of a wet trim is more difficult to achieve because sugar leaves will curl in toward the buds as they dry, making the job more difficult. Handling dried buds during trimming might result in the loss of strong resin crystals due to the agitation caused by the process.

Drying Room Conditions

Whatever method you use to trim your product, it is critical that the drying chamber be set up in the proper circumstances. You’ll need a cold, dark atmosphere with temperatures ranging from 59 to 71 degrees Fahrenheit and humidity levels at or around 50 percent. Yes, even after the growth process has been done, you must continue to be careful with temperature and humidity conditions.

The Drying Process

If you want to utilize the wet trimming approach, you will need to spread them out across a big surface area in order to get the desired results. Because aeration is critical, you should avoid placing the flowers on a flat surface such as cardboard or newspaper, as the buds may dry unevenly on these surfaces. The use of wire mesh or netted drying racks is more advantageous. This allows circulation to reach all corners of the room and reduces the likelihood of wet air pockets forming. Make sure to give yourself enough space to spread your crop out evenly, with a tiny bit of space between buds, in order to get the best possible outcomes.

Excessive hurrying through the process and exposing your crop to high temperatures will almost surely result in worse quality, poorer flavor, and even the possibility of a “bad and unpleasant high.” Good luck explaining it to your investors or to a discerning dispensary that has a slew of producers fighting for shelf space in their establishment.

  • Temperature and humidity levels are measured with a thermo hygrometer. Air conditioner
  • Dehumidifier
  • Humidifier
  • Portable heater
  • Thermo hygrometer

Ensure that you inspect your crop on a regular basis, generally every three to seven days. With each inspection, they will get considerably drier and more comfortable. It will be clear that your buds have been adequately cured when they break easily in your hands and show no symptoms of stringiness or wilting. If you see any bendiness when you twist gently, this indicates that there is still water present and that they are not yet ready to be transferred to jars.

Ideal Temp And Humidity For Grow Tents

All of the growth advice out there may be extremely deceptive. It frequently gives the impression that you must do everything exactly or else your plants will perish. The reality is that cannabis is quite simple to cultivate. Apart from providing it with light and water, there isn’t much more you need to do. However, if you want to optimize your harvest, you’ll need to make sure that the circumstances are optimal. That’s exactly what all of the grow manuals will tell you. And the circumstances of the environment are among the most essential considerations.

Continue reading to find out more.

Ideal Temp And Humidity For Grow Tent

It is possible to be misled by all of the increasing advice out there. It frequently conveys the impression that you must do everything properly or your plants will perish in the process. To tell the truth, growing cannabis is a simple process. Apart from providing light and water, there isn’t much more you need to do. It is necessary to create the best possible circumstances for your crops if you want to optimize their yield.

Everything you learn from grow instructions is exactly this. And the conditions of the environment are among the most significant factors to consider. So, what is the optimal temperature and humidity for marijuana growing in a grow tent, exactly? Find out more by continuing to read.

  • Stage of seedlings: 75° – 85° Fahrenheit / about 70% relative humidity
  • In the vegetative stage, the temperature should be between 70 and 85 degrees Fahrenheit with around 40% humidity (do not exceed 55 percent). In the flowering stage, the temperature should be 65° to 80° Fahrenheit with 40 percent humidity (do not exceed 50 percent).

Because the cannabis plant’s requirements vary depending on its stage of development (it is technically a different plant as a seedling than it is as a full blooming adult), the humidity and temperature must alter to accommodate these variations. Most professional growers have many rooms (or numerous large grow tents), with each area containing plants at different stages of development. This normally entails a blooming and vegging room, as well as a third room for seedlings and transplants. This makes it simple to maintain environmental management while also allowing for twice as many harvests each year.

First, let’s take a look at the two tools you’ll need to keep the temperature and humidity levels in your grow tent at their optimal levels at all times.

Tools Needed To Maintain Ideal Temp And Humidity

In order to keep your grow tent in the best possible condition for healthy plants, you’ll need several essential instruments for measuring the environment around it.

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My guess is that thermometers have been around for a long time, but if not, they are a basic instrument that has been around for more than a hundred years and can tell you what the temperature of your surroundings is. The efficacy and fancifulness of thermometers differ. In general, a decent digital thermometer will be the most effective tool for the job. Although a wall-mounted model is preferable, keep in mind that it will only measure the temperature of the area in which it is installed. A tiny portable thermometer that you can easily carry around your tent will allow you to collect precise readings at various locations, especially near all of your plants, so be sure to have one on hand.

This isn’t a problem if you have a small grow tent with only a few pots in it, as you well know.

Using your portable thermometer, you may determine whether the readings from your air conditioner (which will have a thermostat) and your portable thermometer are consistent.

You must base your judgments on solid facts, especially if you are running a business or semi-commercial enterprise.


An analog hygrometer from the good old days. This instrument monitors the quantity of water vapor present in the atmosphere. In the same way as thermometers are available in both wall-mounted and portable forms, this is another straightforward instrument. You should have a fixed hygrometer as well as a portable hygrometer for the same reasons that you have a thermometer, which we discussed before. You may also acquire a device that measures both temperature and humidity in one convenient package.

It is possible for excessive humidity to damage your entire garden, and it might happen without much notice to you.

If your buds become infected with bud rot, the game is ended (cue Ice-T on the car shield commercial).

You’ll be alerted as soon as it begins to climb to dangerous levels, allowing you to respond in time to save your plants’ lives! The operation of a hygrometer is actually extremely intriguing (at least to me), and you can learn more about it here.

Ideal Conditions For Seedling Stage

As previously stated, the temperature should be between 75 and 85 degrees Fahrenheit with a relative humidity of 70 percent. Seeds must germinate in order to grow, and germination necessitates the presence of humidity and heat (just not too much). The seeds will sprout when these conditions are satisfied and enough time has passed. The little young plants will poke their heads out and begin to shoot upwards once the seeds have sprouted. Even if there isn’t a lot of difference between seedling and the early leafy developing stage, the little that is required can be a game changer if it isn’t done correctly.

Perfect Conditions For The Vegetative Stage

Ideally, you want the temperature to be at 80° or so throughout this period, with the relative humidity (RH) around 40 percent. According to what you may have observed, there is no difference in temperature between the sowing and growing periods. In contrast, the necessity for humidity represents a significant shift. Seedlings thrive in wet air, but too much moisture soaking those leaves might lead to the apocalypse of the grow tent, which I am sure you do not want to experience! This large fall in necessary humidity between sowing and vegging can be attributed to the fact that leaves prefer drier air during this time period.

As a result, they become ill and absorb less light and nutrients, resulting in a weakening of the crucial photosynthetic activity in the process.

Ideal Temp And Humidity For Bloom

During the last stages of growth, plants require slightly colder air and lower humidity levels than they were previously used to experiencing. In terms of technicality, the humidity window becomes narrower in this phase compared to the preceding phase. This phase can have humidity levels ranging from 40 to 50 percent, which is a bit lower than the previous stage of development. This is due to the fact that buds are fickle in their behavior. When there is too much heat, the air’s ability to hold water increases.

Keeping all of this in mind (or, better yet, writing it down in a notebook you carry with you) might assist you in making your grow tent the optimal environment for your plants.

The major reason temperature matters is that it has an influence on the ability of the air to contain water, which brings us back to the topic of humidity.

However, if you make a mistake and the weather becomes too cold or too hot for a short period of time, you will not lose your crop.

If, on the other hand, the humidity rises to dangerous levels and your plants get bud rot, you have a serious problem on your hands. As a result, make sure you have enough fans in your grow tent at all times.

Ideal Grow Tent Humidity And Temp: Final Thoughts

Maintaining the correct temperature and humidity levels in your grow tent is critical to optimizing the amount of marijuana you can harvest from your plants each harvest. However, the temperature and humidity that your plants require do not remain consistent during the growing process. Plants require warm and humid temperatures throughout their initial stages of development. Increasing the temperature and humidity is necessary as they progress through the phases of the process. If you follow the instructions above, your plants will not suffer any negative consequences as a result of their exposure to a bad environment, and they will repay you with abundant harvests.

Growing marijuana is straightforward, but producing marijuana and harvesting the greatest possible crop necessitates meticulous attention to detail.

Some deep budget brands perform admirably and allow you to save a significant amount of money.

How To Lower Humidity In Grow Tent Or Grow Room

Keeping the relative humidity under control may be a challenge for indoor growers, and it can occasionally lead to difficulties. Experienced indoor growers understand that maintaining the proper humidity level in your grow tent is important to the success of your indoor plant growing endeavors. If the humidity level in your grow tent is too high, learn how to control the humidity level in your grow tent. High humidity levels can cause delayed growth, bud rot, fungal development, mildew, and mold to appear on the leaves of plants.

The humidity level in your grow tent should not be more than 70%.

Don’t be concerned; the very items that you’ll find in your grow tent may be the solution to keeping the humidity level in your grow tent at an optimum level.

Understanding Relative Humidity

Let’s start with a little scientific lesson: humidity is defined as the amount of water vapor present in the air. At the same time, relative humidity may be defined as the relationship between present absolute humidity and the greatest potential absolute humidity. In layman’s words, relative humidity is the point at which the air becomes entirely saturated with water vapor and is no longer able to contain it any longer. Keep in mind that there will always be some amount of water vapor in the air.

When the temperature within your grow tent is greater, more water vapor will be able to be held in the air. Heat in a grow tent encourages water to travel more quickly through the air, resulting in a greater level of humidity in the environment.

Why High Humidity Is Bad And Causes Problems

So you’ve been informed that high humidity is essential for the strong development and health of your growing plants. Do you believe it? Humidity is extremely beneficial to plants. However, although this is true, overly high humidity levels in your grow tent might cause more harm than good to your plants. If youDO NOTwant your grow tent to:

  • Bacteria and molds thrive in this environment, which is ideal for them. Allowing your floral plants to succumb to bud rot or botrytis Increase the hazard posed by pests and pathogens
  • Prevent your plants’ transpiration, or exchange of air, from occurring
  • Encourage the growth of undesirable microbiological organisms
  • Clog the stomata, reducing carbon dioxide intake, which is necessary for optimal photosynthesis to occur
  • Make the roots inactive by reducing their capacity to absorb water on their own own
  • Reduce the rate at which your plants absorb nutrients
  • Reduce the amount of produce produced by your plants.

Then it’s time to figure out how to keep the humidity levels in a grow tent as low as possible for the duration of the grow.

Importance Of Low Humidity In A Grow Tent

When it comes to humidity levels, it is important to remember that a low humidity environment in your grow tent may do wonders for your plant. Homogeneous conditions and moisture build-up in a grow tent might cause your flower or buds to get moldy and die. Other problems associated with excessive humidity include:

  • It is possible for white mold to irritate your leaves, preventing them from taking in water and oxygen, as well as light. Rust fungus: This fungus causes rust patches on the leaves of plants. Root rot occurs when the soil is excessively damp for an extended period of time.

Grow Tent Size

It is important to consider the size of your grow tent from the beginning since you must guarantee that all regions are covered by a reasonably low level of humidity in all places. For example, a44 grow tent requires 40 percent of the total energy, but a55 grow tent requires at least 65 percent. My 4×4 grow tent can accommodate a home dehumidifier, thus a small dehumidifier that can absorb 8 to 10 ounces of moisture each day will enough for a 2×2 grow tent.

What’s the best grow room temperature?

Although temperature changes, it is necessary to provide you with an understanding of how to regulate humidity. Make certain that you have a thermometer and a hygrometer on hand. Clones or seedlings prefer temperatures between 74 and 78 degrees Fahrenheit, although vegging plants may live at temperatures as low as 70 degrees Fahrenheit. In order to flower, flowering plants require greater temperatures of 88-75 degrees Fahrenheit than plants ready to harvest, which can tolerate temperatures of 65-74 degrees Fahrenheit.

What’s The Best humidity level?

Plants flourish in a variety of humidity levels throughout their lives, at all stages of development. Seedlings or clones require 70 percent to 75 percent humidity because plants need time to grow their root systems, which forces them to rely on their leaves to absorb water until their root systems are fully developed. Having enough of moisture in the air is essential for feeding your newborn plants. It is for this reason that indoor producers employ propagation trays or humidity domes to accumulate moisture.

Flowering plants require 40 percent to 50 percent humidity in order to provide a pleasant environment for their leaves to breathe.

When it comes to indoor horticulture, humidity is a critical factor to consider.

In order to be successful as gardeners, we must be aware of the humidity levels that are appropriate for different phases of plant growth and different plant species.

Humidity, in conjunction with temperature and light, can assist producers in raising healthy, vigorous plants that produce abundantly and efficiently.

Here How To Lower Humidity In Grow Tent

According to everything I’ve said thus far about the importance of high humidity, it can also be harmful if the levels get excessively high. Here are some tried-and-true and simple methods that indoor gardeners have used to help minimize humidity in their grow tents:

1. Avoid overwatering your plants

I’ve already said that high humidity is necessary, but when the levels grow excessively high, it may be hazardous to health. Here are some tried-and-true methods that indoor gardeners have used to control humidity in their grow tents:

2. Use a Dehumidifier Inside your Grow Tent

I’m confident that you’re familiar with our old acquaintance, the dehumidifier. When the air in your grow tent becomes too humid, a dehumidifier can assist to extract the excess moisture from the air, therefore decreasing the humidity levels. You will most likely have to spend more money on this because a grow tent will normally require the use of an industrial dehumidifier. We must make significant investments in resources in order to assure overall plant development and yields. If your site is already humid, I recommend that you use a high-quality dehumidifier that is connected to a drainage system.

  1. If possible, your dehumidifier should be capable of eliminating at least the same amount of moisture from the air as your plants absorb on a regular basis.
  2. Learn more about how to select the most appropriate dehumidifier for your grow tent.
  3. Some dehumidifiers include an automated shut-off option that activates when the water reservoir is full.
  4. Therefore, the entrance and outflow of a humidifier are both located within your grow tent, which might result in the space becoming overheated.

3. Check your plant density

Naturally occurring carbon dioxide is released by plants, which causes the temperature in your grow tent to rise. As a result, moisture accumulates and the relative humidity rises. Increasing the amount of plants in your grow tent might cause the air in the tent to get displaced, preventing other regions from receiving fresh air and carbon dioxide. Continue reading to learn how to determine the optimal amount of plants that should be accommodated in your grow tent. Keep in mind that if your grow tent does not have adequate dehumidification and ventilation, the water vapor transpired by your plants will be retained.

4. Remove stagnant water

Remember how I said you didn’t have to spend a lot of money attempting to lower the humidity levels in a grow tent? Well, I was right. Here’s one of the most cost-effective strategies we can employ! As indoor producers, it is our job to ensure that our grow tents have adequate drainage so that stagnant water does not pool on the ground and contribute to excessive humidity. Water that has become stagnant has the disadvantage of reducing molecular oxygen concentrations to the point where bacteria may develop and flourish.

One of our most common mistakes is to leave water reservoirs exposed or to allow stagnant water to develop puddles on the floor, which causes moisture to be released into the air. There’s nothing worse than having your grow tent turn into a breeding ground for bugs and pathogens.

5. Improve ventilation by adding more fans

In order to enhance ventilation in your grow tent, I propose adding extra exhaust fans or increasing the speed at which the fans rotate. Increasing the quantity of airflow in the grow tent is the most practical technique to assist raise the amount of oxygen available. Utilize an atmospheric controller with a humidity setting, if feasible, to automatically adjust the fan speed to achieve the desired level of humidity. Another option is to use a duct fan or open a window to force moisture out of the grow tent, which is a straightforward solution.

  1. This form of ventilation will lower humidity levels since the positive pressure within the grow tent provides enough air movement to provide a mild breeze across the whole tent.
  2. I should caution you against depending solely on oscillating wall fans to provide proper air circulation; these fans might fail to do so since they can only lessen the temperature on the canopy.
  3. I now recommend that you purchase floor fans to draw air through the canopy and guarantee that carbon dioxide is distributed evenly.
  4. Using a hygrometer controller to power fans is a dependable automation method, according to my experience.
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6. Create air holes

Making large or narrow openings in your grow tent might help you manage the flow of air in your growing environment. To reduce humidity, expand the openings in the ceiling to guarantee that more air enters than escapes from the ceiling. Take care not to allow any unnecessary light into the room.

7. Purchase an air conditioner

It is well-known that the primary function of an air conditioner is to chill the air and reduce humidity levels in the surrounding area. The gadget extracts heat from the air by compressing it and using gas to do so. In addition to generating condensation, this procedure eliminates moisture from the air in a highly efficient manner. Large air conditioning equipment, on the other hand, tend to operate on short cycles or for short periods of time, creating an unpredictable climate for your plants.

In addition, there is the issue of frequent variations, which can cause the temperature in your grow tent to skyrocket to dangerous levels.

This may also be used in conjunction with a fan to assist maintain a cool climate in your grow tent by minimizing the amount of water vapor produced.

As a result, you must choose a suitably sized air conditioner for your grow tent that is capable of drawing sufficient water from the surrounding air. It is important to remember to clean the filters since clogged filters hinder proper airflow, which causes the humidity to rise.

8. Insulate and seal your grow tent

When it comes to controlling humidity, one of the most important things to consider is making sure your grow tent is properly insulated and sealed. I construct a substantial barrier between the outside environment and my grow tent by insulating it with foam insulation. I am less concerned about my plants being threatened by external sources as a result of this.

9. Use grow equipment wisely

I’d like to caution you that grow equipment, such as grow lights, might cause the temperature in your grow tent to rise significantly. Consider purchasing a grow lamp that does not produce a lot of heat. If the temperature in your grow tent is too high, switch off the lights to let the temperature to decrease. Allowing your lights to go to sleep can also help you save money on your power bills.

10. Make use of absorbent soil

As indoor gardeners, we need to be aware with the many types of soil that are acceptable for our plants’ needs. Utilizing soil that has the ability to retain water underneath a grow tent is essential for lowering humidity levels. I recommend that you use sandy soil to reduce evaporation rates and the amount of water that is exposed to the sun. Alternatively, perlite is an option, although sandy soil is less expensive—a nice reminder to replace the soil on a regular basis. I’ve also noticed that utilizing lime or baking soda offers the same benefits as using sandy soil when it comes to growing vegetables.

Always choose surfaces that are absorbent.

11. Consider defoliating your plants

Another option that is more cost-effective is presented below. Plants with large leaves, such as leafy plants or plants with large leaves, might cause the humidity levels in your grow tent to rise. I normally try to reduce the amount of humidity in the air by removing some leaves from the trees.

To sum it up…

Indoor producers must keep track of both humidity levels and temperature readings, as well as the relationship between the two. We will be able to better understand how environmental conditions influence the development and survival of our plants in this manner. Generally speaking, plants will have a difficult time transpiring if both humidity levels and temperature levels are high. As a result, growth and development are slowed significantly. Furthermore, ventilation is one of the most important factors affecting humidity levels in a grow tent.

  • To maintain high-quality growth and increased yields, it is necessary to keep humidity levels under control.
  • Remember, first and foremost, you must comprehend the contextual conditions.
  • Alternatively, if this is not practicable, there are low-cost alternatives such as the use of exhaust fans, a hygrometer controller, monitoring ventilation, or managing plant density.
  • If you use appropriate gardening tools and maintain adequate ventilation while keeping relative humidity levels low for your plants, they will appreciate you.
  • She contributes to a variety of online media and websites.

With significant expertise in both hydroponics and aquaponics, she is well-versed in the art of indoor growing. This contains hydroponic gardening equipment such as grow boxes, grow cabinets, grow lights, and other issues related to hydroponic farming.

Ideal Temperature and Humidity for Grow Tents

When you make a purchase after clicking on one of the affiliate links on this site, Growing Marijuana World may get a commission. For a complete list of affiliates, please see the sidebar. The soil and the amount of light necessary for marijuana cultivation are, in my opinion, the two most important considerations for beginner marijuana producers. It’s most likely because of the illumination. If you are serious about increasing the number of buds you are able to harvest, then understanding about the temperature and humidity needs for marijuana cultivation is essential.

Between 20 degrees Celsius and 30 degrees Celsius is the optimal temperature for the vegetative (growth) stage of the plant (68F to 86F).

The optimal humidity ranges from 40 percent to 60 percent relative to the surrounding air.

What is the Best Temperature for Vegetative Stage in a Grow Tent?

The key to having success with your marijuana plants is to try to recreate the temperature that would be outside in the weed plant’s native environment throughout the growth season. During the afternoon in the veg stage, you want the environment to be as hot as possible to resemble summer days. If you can raise the temperature in your grow tent up to 30 degrees Celsius (86 degrees Fahrenheit), it will grow like a weed. Allow the tent to drop down to the lower 20s (68 to 75 degrees Fahrenheit) at night, if at all feasible.

I have an essay on several methods of heating your grow tent that I believe you will find useful when trying to figure out the best method of heating your grow tent for your needs.

It may be found by clicking here.

What Temperature Should my Grow Tent be During Flowering?

When it is time to switch the lighting schedule and encourage the marijuana’s flowers/buds to begin developing, you are now attempting to replicate the meteorological conditions of fall. In other words, reduce the temperature in the grow tent and potentially supply a different type of lighting to the plants. You might retain the temperature at its current level, but this would not expedite the procedure for you. My advise is that when you switch your lights to 12/12 timing, you should drop the temperature of the tent by up to 5 degrees (down to 77 Fahrenheit).

  • During the day, keep the tent’s temperature between 20 and 25 degrees Celsius (68 and 77 degrees Fahrenheit), however you may go as low as 18 degrees Celsius. While in blooming stage, lower temperatures (less than 28C/82F) will allow the trichomes to be more effective than if the temperature in the grow tent remained at the same level as it did during the vegetative stage. Reduce the temperature by a few degrees at night, similar to what you did during the vegetative period. As an extra benefit, when you believe you will be cutting down the plants in two weeks or less, raise the temperature differential between the night and day even more than you already have. I would only reduce the temperature at night, not during the day. Your buds will become larger and more thick as a result of this practice. It informs the plants that their growing season is coming to an end and that they must generate those large buds as soon as possible.

What Should My Grow Tent Humidity be for Marijuana?

As previously indicated, the humidity in the grow tents should be approximately in the region of 40 percent to 60 percent. If you want to maximize your chances of success, there are a handful of things you should keep in mind.

  • During the vegetative stage, it is preferable for your pot plants to be cultivated in greater humidity, and reduced humidity during the flowering stage. During the blooming or budding stage of the plant’s growth, it is critical to gradually reduce the humidity as the plant gets closer to harvesting. This is a representation of what happens outside throughout the fall season.

What Happens if Humidity is too Low in Grow Room?

If you are growing in a grow tent or room, it is conceivable that you will not have adequate humidity during the vegetative stage. One of the disadvantages of this occurring is that your plants’ growth will be stunted. Stomata on your plants might potentially close, preventing them from receiving the oxygen exchange they require. It is possible that your plants will not perish, but their growth will be adversely impaired. This is, of course, an extreme example in which the humidity is extremely low.

During the blossoming period, it is OK to have lower humidity levels that are near to 40 percent. 40 percent is not only not dangerously low, but it is also low enough to be beneficial for your plants.

How Do You Keep Humidity High in a Grow Tent?

Maintaining humidity in a grow tent requires consideration of two factors. Providing a source of humidity and preserving the humidity in the tent as long as feasible are two important considerations. Let us have a look at both.

  • It shouldn’t be difficult to create humidity in a grow tent, one would assume. In my home, I have a cool mist humidifier with a humidity setting, which means it turns off when the required level of humidity is reached. Like THIS ONE on Amazon
  • It’s similar to
  • One additional method that I’ve done in the past is to fill a 5-gallon pail halfway with water and submerge an aquarium heater in it. This is a great method to not only benefit from the water and humidity, but it is also a lovely way to assist in heating a smaller tent. I’ve written a post that has some excellent suggestions for heating grow tents. Make sure to have a look at it when you’re through here. What is the best way to heat a grow tent?
  • The use of a 5-gallon bucket filled with water and an aquarium heater placed in the water has also been successful in the past. Water and humidity are beneficial, but it is also a pleasant approach to assist in heating a smaller tent. A excellent post about heating grow tents is available on my website. When you’re through here, make sure to have a look at it. Instructions on how to heat a grow tent are provided.

Why is There Condensation in My Grow Tent?

If you allow the humidity level to rise over a certain threshold, you face the danger of condensation forming within the tent. You might also wind up with mold, which is something you really don’t want. To keep the tent at the proper humidity level, you may either invest in a hygrometer such as this one (which detects moisture/humidity in the air) or do what I previously mentioned and use a humidifier, being sure to obtain one that shuts off when the air in the tent reaches the desired humidity level.

Do You Need Ventilation in a Grow Tent?

The risk of condensation forming in the tent increases if you allow the humidity level to become too high. If you don’t take precautions, mold may grow in your home. A hygrometer (which detects moisture/humidity in the air) may be purchased, or you can use a humidifier (which should be one that shuts off when the air inside the tent reaches the desired humidity level), as previously mentioned.

See also:  What Is Minimum Tent Weight

How Do I Keep My Grow Room Warm When the Lights are Off?

It is preferable to have the temperature decrease a little when the lights are turned off, but it is still necessary to maintain it warm, especially during the vegetative stage. For instance, you may use an integrated thermostat on a heater to achieve this goal. If you’re searching for further suggestions, I’ve included a link to a post I wrote about heating grow tents higher up on this page for you. Make sure to have a look at it.

How Can I Keep My Grow Tent Cool in the Summer?

This is one of those things that would have to be addressed on an individual basis because every circumstance is unique. Because you are utilizing a grow tent rather than a grow chamber, you have the advantage of being more portable. Place the tent in the most shady and coolest region of your home. Another alternative is to relocate the tent such that air conditioning is blowing towards the structure. The use of an internal fan and leaving the tent zipper open at times when the lights are on is still another option.

I hope you were able to take away something beneficial from this essay that you can use to your own growth circumstances.

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Articles on Growing Marijuana in the Real World Is it okay to use negative pressure in a grow tent?

What Is The Best Humidity For Growing Cannabis Plants?

Cannabis is a high-value plant that has come to be farmed mostly indoors because of its great sensitivity to environmental factors. When it comes to cannabis growing, each stage needs a unique type of tune-up in order to achieve optimal growth and high-quality harvests. Not only does humidity play a role in the growth of this magnificent plant, but it also plays a role in the correct curing of cannabis, as well as in the use of improper storage containers and storage conditions when cannabis is in storage.

Drought and high humidity are two environmental conditions that might influence the development of cannabis. Water vapor content in the air may be described as the amount of water vapor present. The following are the three types of humidity that are commonly encountered:

  • Specific humidity – The specific humidity of a given location is defined as the ratio of the amount of water vapor to the amount of dry air in the atmosphere. Absolute humidity is the actual quantity of water vapor present in a particular region
  • It is measured in percentage. When a relative humidity measurement is made, it is the difference between the quantity of water vapor that is actually present in an area and the amount of water vapor that the region is capable of holding.

Specifically, specific humidity is the ratio of the quantity of water vapor present in a given region to the amount of dry air present within. It is the actual amount of water vapor present in any particular space that is measured as absolute humidity. When a relative humidity measurement is made, it is the difference between the quantity of water vapor that is really present in an area and the amount of water vapor that the region is capable of holding;

What Factors Affect Relative Humidity Control For Cannabis?

When it comes to finding the proper relative humidity for growing cannabis plants, there are three important considerations to keep in mind. There are three of them: geography, genetics, and developmental phases. Despite the fact that there are less severe and more varied scenarios, these three have the biggest influence.


Because of the temperature relationship discussed above, colder places have less moisture in their air. Growing cannabis in these conditions necessitates the rise of relative humidity to an optimal level. However, humidification management is less necessary in hot or tropical locations because most cannabis plants thrive in environments with greater relative humidity.


Over the years, a large number of different cannabis cultivars have been created. While certain cannabis species thrive in warmer and more humid environments, other cannabis species thrive in colder and less humid environments.

Growing Stages

The cannabis plants need fluctuations in humidity conditions throughout their life cycle, from germination to late blooming. Because each step involves a unique set of metabolic events, the relative humidity requirements for each stage differ.

Why Is Humidity Important For Cannabis Plants?

To understand how humidity impacts the growth of cannabis, it is necessary to first understand the method by which the plant breathes. The sugars created during the photosynthesis process must be transformed into energy that will be utilized to promote the development of the plant’s cells. The cannabis plant must absorb carbon dioxide from the surrounding environment in order to transform the carbohydrates, mostly glucose, into energy and oxygen, which are then released back into the environment.

  • When this procedure takes place, some water from the plant’s water reservoir is lost to the environment, which is harmful to the ecosystem.
  • There are two possible outcomes: A large reduction in the water concentration gradient occurs when the air is wet (high relative humidity), which is due to the greater amount of water vapor present in the air.
  • Strong water loss occurs when the air is dry (low relative humidity), as a result of a high water gradient produced between the plant and the surrounding environment.
  • Briefly stated, relative humidity is critical to the growth of cannabis plants because it affects the respiration process and its associated activities, such as the loss of water.

In order for a cannabis plant to reap the full benefits of relative humidity, it must be kept at its optimal humidity level. It will also be beneficial if the humidity is maintained at a steady level for a prolonged length of time.

Should Humidity Be Low Or High For Cannabis Plants?

Cannabis plants are cultivated in a relative humidity range of 70-40 percent, which is ideal for their growth. This is neither an excessively high nor an excessively low humidity level. As previously stated, both extremes of relative humidity have the potential to produce cannabis plant stagnation, as explained above. In addition, it is important to be aware that high humidity might encourage the formation of mold, which can negatively impact the growth of your marijuana plants.

What Humidity Should I Have In My Grow Tent?

When growing cannabis in a grow tent, it is important to keep environmental factors like as humidity and temperature under control. It is well-known that different phases of the cannabis plant require varied amounts of humidity, but it would be beneficial if you could keep the humidity in your grow tent quite high for cannabis seedlings when they are in the early stages of growth. The quantity of humidity in your cannabis grow tent is influenced by a number of things. These are some examples:


If the lights in your grow tent are left on all of the time, the temperature of the enclosed air is elevated, which in turn raises the relative humidity. Grow chambers with insufficient lighting circulate chilly and dry air (low humidity).


The relative humidity in your grow tent will decrease as a result of enhanced air circulation if your grow tent is properly ventilated. It is necessary to provide ventilation to mature cannabis plants, which demand a low relative humidity.

Frequency of Watering

It is more effective to water cannabis plants under a grow tent since it boosts the plant’s water absorption through the roots. The high rate of water intake by the plant increases the rate of water loss via the leaves, increasing the humidity in the space. It is this increased moisture that allows the marijuana plant to maintain its health by regulating its respiration process (see Figure 1). Again, watering should be optimized to maintain the grow tent at the optimum degree of humidity.

What Humidity Is Good For Cannabis Flowering?

It is advised that the relative humidity of a blooming cannabis plant be between 40 and 50%. The moisture content has been decreased to this level primarily to avoid the formation of mold, which is particularly dangerous at this point. Isn’t it true that a mold infection on a single cannabis blossom may completely spoil a whole harvest? Consequently, lowering the humidity at this time is quite important and should not be disregarded. When the cannabis comes near to harvesting, it is also possible to lower the humidity below 40% of the surrounding air.

In conclusion, it can be stated that humidity is a necessary condition for the growth of cannabis plants to be successful.

However, using either manual or automatic hygrometers, it is simple to determine the relative humidity levels in cannabis growing facilities.

If you cultivate your cannabis plants under a grow tent, you will also benefit from the automatic lowering of humidity levels that will occur. This is accomplished by the employment of dehumidifiers and fans of commercial scale.

The Key Element Most Grow Rooms Neglect and 3 Reasons To Stop –

It’s easy for new growers to overlook the need of maintaining optimum humidity levels. When it comes to the cultivation process, this is a critical step. Humidity, on the other hand, is a temperamental creature. Growing cannabis indoors has proven to be a difficult task for even the most experienced producers around the country. The cannabis plant is extremely sensitive to fluctuations in humidity, which can be extremely detrimental to a grower’s productivity. That’s where Anden comes in, assisting cultivation firms in growing more effectively via the use of excellent solutions that are tailored to their individual growth requirements.

Ideal Humidity Changes for Each Cannabis Growth State

In the seedling stage, relative humidity levels should be 70 percent or more; during the blooming stage, relative humidity levels should be as low as 30 percent. As a result, it is critical to maintain a wide variety of indoor humidity levels throughout the whole growth phase. This necessitates having simple control over the humidity levels in your grow space. Seedlings and clones | Optimal levels: 70-80% of total Because the root system of seedlings and clones has not yet developed, high humidity levels are beneficial to their growth.

  1. Vegetative |
  2. As the plant begins to take root during the vegetative phase, humidity levels can be reduced by 5 percent every week until the plant is well established.
  3. During this period, the water will evaporate via the leaves of the plant, aiding in the cooling of the plant and the natural addition of more humidity to the air.
  4. Optimal levels are 40-50 percent of total.
  5. Any humidity level more than 60% has the potential to harm the plant, which relies on moisture from the soil to survive and thrive.
  6. Less than 40% of the plants are in bloom.
  7. This can, in turn, serve to increase the production, flavor, and look of the plant in the long run.

An Organic Approach to Cannabis Cultivation

Every producer is growing cannabis in an unique set of environmental parameters – temperature and humidity – that are intended to produce a certain strain of marijuana. Unfortunately, when inadequate environmental solutions allow mold and funguses to infiltrate your crops, they have the potential to harm your harvest. When it comes to completely eliminating these dangerous factors from your grow environment, there are only two options:

  1. You can employ chemicals, which can have an impact on the quality and potency of your crop
  2. However, this is not recommended. Create a balanced atmosphere for your crop to thrive in if you choose the organic method of growing food.

When you provide your cannabis with a healthy, organic environment to develop in, you can avoid water from collecting on the leaves of your plants in its physical form. As moisture remains on your crop for an extended period of time, the greater the likelihood that destructive mold or fungus may spread to the rest of your harvest. In reality, 97 percent of the water that is applied to cannabis plants evaporates into the atmosphere.

In other words, for virtually every gallon of water you provide to your plants, another gallon must be taken from the air in order to maintain balanced levels that will prevent plant mold and disease.

97% of the water dispensed to cannabis plants ends up in the air

Maintaining a balanced atmosphere entails more than just making sure your temperature and humidity are at the proper levels. If you want to stimulate growth while also conserving energy and, ultimately, money, you must create the best possible atmosphere for yourself to succeed. For example, if you theoretically want to create an atmosphere with a temperature of 75 degrees and 50 percent humidity, it will be hard to maintain that precise temperature and humidity level for an extended length of time.

  • To maintain a balanced environment, you want to stay as near to those environmental criteria as feasible.
  • The only issue with this is the cost connected with operating an air conditioner nonstop all day and all night.
  • As a result, every second it continues to operate longer than it should represents additional money spent on energy.
  • Your air conditioner won’t have to work as hard to eliminate moisture, and it will be able to simply chill your growing space.
  • Those two systems can work together to provide a more balanced growth environment if the correct controls are in place.

Control Your Grow

Find out more about Anden cultivation systems, or get in touch with a provider near you, right now.

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