10 Ways on Raising Humidity in Grow Tent

Viewing your plants to dry out is your worst nightmare for any grower. If we put issues like stressed plants up, immature plant roots on top of that, that’s the doom’s day for you.

Guess what, these issues have their origins into one particular cause- Low humidity in mature room.

Thus, we’ve decided to craft an all-in-one guide on increasing humidity in mature tent. We’ve broken down the grow humidity basics, perfect humidity levels in grow tent and 3 phases on how to raise grow kayak humidity.

Grab a cup of coffee, buckle your seatbelt and let’s dive deep to the manual –

Grow Room Humidity: The Basic Knowhow

Before we begin, it’s time to remember a few science.

But that is not how gardeners acknowledge it.

There are three ways to deal with humidity- complete, specific and relative. So, we’ll just stick to that anyhow –

What Is Relative Humidity?

The relative humidity is a percent, which shows up the proportion of present moisture content and also the most potential moisture content of a particular quantity of air.

The formula states –

The higher the grow room humidity percentage is, even more vapors take place in the atmosphere, and the more humid your grow room feels. And vice versa.

That being said, there are very active effects of other environmental factors like-

Seems confusing? The following section is solely for you, then-

RH and Other Environmental Factors

Humidity and Temperature

Humidity is inversely related to the temperature of your grow area. While temperature increases, the air’s ability to hold vapor decreases. So, you’ll have a low RH beneath the lights, in which the temperature is greater than cooler areas such as the ceiling or vent openings.

Humidity and mild

Light does not have a direct impact on the humidity of a certain space. But typical grow lights are absolutely heated creation, which affects upon the humidity of the room. If you do not ensure a proper air-cooling system round the lights, this will eventually impact on the humidity.

That being said, with cooler lights like LEDs is a more economical option from every point of view.

Humidity and Ventilation

Ventilation impacts on the atmosphere inflow and outflow of the grow room. So too much venting will bring on faster air circulation, which won’t let the grow room become humid.

On the other hand, slow ventilation will trap the air and the humidity and temperature beneath it.

Therefore, neither an excessive amount of ventilation nor too slow venting is good for developing.

Abundance of water resources provides more water surfaces to source the vapor type. More vapor in air means more% of RH.

If these surfaces are near the intake tubes or vent holes, it is more likely vaporize, and make the air moister.

The very best way to measure your grow room humidity is to use a build space humidity meter(hygrometer). There are many models out there on the market, and the majority of them are electric thermo-hygrometer combos.

However, there are two sorts of electric thermo-hygrometer combos available. If You’re interested, here is the way they operate –

Electricity passes through a ceramic substance that’s in air. With increased humidity(water vapor), the porcelain crowns, and that changes its resistance. And the level of change is transformed into a change of humidity.

Capacitive Electric Hygrometer

The warmth of the air between the metal plates defines how much control these plates can hold. Thus, the degree of humidity comes out from numerical values.

Which Are The Ideal Grow Room Humidity Levels?

In various stages of a plantation, their humidity requirement differs. A rule of thumb is, relative humidity should never exceed 70% in any condition.

But, we want more specific humidity requirement in mature tent. And it is-

Table: Ideal develop room humidity for each grow phases

Seedlings/Cloning70-75percent To maintain plant roots stay growing and overburdened. Early Vegetative Stage60-70percent To allow both roots and leaves to intake water and dampness. Early Flowering45-55percent To allow the plant stay in neither too cold nor too hot atmosphere. Late Flowering40 percent To prepare the plants for reaping Harvesting35-40percent to not make any molding issues.

Big question! But the answers are almost Here are the replies –

It Enables You To Control Your Plant’s Nutrition

Grow plants will need to keep intaking water through their roots and leaves. When the humidity is sufficient, they absorb moisture (water) throughout their leaves. This allows them drink less water through the roots.

On The other hand, lack of humidity from the air causes the crops to drag more water. And as we gardeners place nutrients in the water, the more they drink it, the more nutrient they choose.

Summary line? Learning the way to restrain grow tent humidity is the synonym of getting control over the nourishment of the plants.

It Effects on the Health & Growth

Plants love to live at a high humid environment when they are young. And with time, they get mature and asks for a less humid atmosphere.

As a result, the abundance of humidity is an integral aspect to ensure the proper growth of crops, especially when they are tender.

In another way, if plants need to drink more water because of lack of humid air, this will put more strain on the roots. This stress will eventually lead into dehydration, stomata final and the overall health of these plants.

The way you’ll battle low RH level, depends upon your own efforts.

We think the ideal way to boost the humidity in mature tent is by way of a set of activities. These actions would be dependent on your financial plan and intention to provide attempts.

Now let’s get going-

Phase 1: No Price Modification

Within this stage, you can modify your existing grow tent equipment to raise humidity. But remember that these methods won’t fill your humidity gap entirely.

Eliminate Half the Fluorescent Lights

The science is easy here. You already know that humidity decreases with temperature increase. And guess what, fluorescent lighting emit heat.

Simply speaking, fluorescent lighting reduce humidity.

So, removing half of the fluorescent lighting is an easy method to raise the warmth in grow area .

Lower your Fan Speed

Ventilation is almost always a vital part of growing. Without proper ventilation, your grow tent won’t observe an exchange of atmosphere.

People normally put the fan speed at moderate. This helps in conserving moisture at various stages of plant development.

If you set your fans at high speed, then two things will happen-

The atmosphere will dry up quicker than an average speed leading to quite low humidity in mature tent.Vapor won’t have the ability to sit on the leaves leading to low moisturization of the plants.

Thus, it’s very possible that high fan speed can leave your crops .

Now, what to do with all the fan speeds if I wanted to boost the grow tent RH?

In short, set the fan speeds in the lowest possible level.

The reduced fan speed will circulate less grow kayak atmosphere. This will increase the humidity in grow tent air.

Because of this, humid air will be in touch with mature plants constantly. Bear in mind that this method alone won’t require your increase tent RH jumping to 70%.

Modify AC Settings to Drop Temperature

As we have discussed earlier, the temperature fall helps in building humidity.

If your air conditioner fails to cool down the grow tent, then it’ll be impossible to grow the RH level.

See what its thermostat array is.

It is okay if the preceding zero budget approaches weren’t enough for you.

If you are ready to devote a little bit of money for humidification, but with a light wallet, then that is the perfect spot for you.

We’ve gathered up some low budget hacks that might just do the trick for your grow tent without having a humidifier.

So, let us explore these hacks one by one-

Blend some Plants

Increasing Plant density is a superb solution if you can not keep the humidity up in grow room or tent.

Plants release vapor as part of the respiration. With plants that are increased, your increase tent will get increased vapor. Because of this, your increase tent RH will boost up.

As you’re a bit low on the budget, try to get some huge plants.

Larger plants have lots of bigger leaves. Those leaves discharge a humongous amount of water vapor and CO2. Both these byproducts help out plants.

But if you overcrowd the mature area with larger plants, subsequently younger plants won’t get enough share of the nourishment and air flow.


Here the secret is to keep water from the drainage system.

With excess water on the drainage system, your grow tent will see additional water. Which will eventually, show you just how you can get up the humidity in grow tent through controlling irrigation.

But don’t get removed. Increased watering may take out your plant permanently. Additionally, bear in mind that your water bill will increase more than average.

Hang Wet Towels

By now, we know that more water surface means greater humidity.

So, a smart method to produce more water is through this method. Get a pair of flashlights and hang around moist towels inside your grow tent or room.

To get a grow tent of 4×4 ft, 2 wet towels would be sufficient. Also, while hanging the towels, confirm that it does not hamper air flow.

Soak the towels in the morning and then hang those on the first day. Assess every 2 hours to see when the towels warm up. When the towels dry up quickly, then it means that the air lacks moisture.

This is a superb way of controlling grow tent humidity really!

Spread About Water Sources

This is a cheap hack and can be used by many growers.

Here the purpose is to put water trays inside the grow area. The philosophy behind that is exactly the same as before.

Which is- Improved water surface = Improved Humidity.

Thus, handpick some optimum spots within the grow room. A few great spots are- close to an air intake tubing and other passive air pockets.

You might even put wet sponges with every expansion tray. This increases humidity levels close to your grow plant.

Stage 3: Products to Boost Humidity in A Tent

If you’re here, then most probably the previous phases failed. There are two probable reasons behind this failure-

  • Your mature area has intense dryness
  • Your mature place is too big, and those hacks aren’t covering sufficient area

So, it’s time that you opened up your wallet to repair this humidification issue. The methods explained in this stage are the best way to increase humidity in grow tent.

Now, let’s explore the’possible futures’ of your grow place-

If the existing air conditioner is not enough for your grow area then you have to replace it or add up a fresh one.

This time correctly calculate the AC Unit that you require for cooling down your grow place. If you’re adding up a new AC, then compute how much combined-output you will need.

Based on the calculations include up a new AC or substitute the old one.

Change the Floor Soil

Yeah, you heard it correctly. Soil has it is role to play bringing the humidity level also low. So, how to add warmth to cultivate tent just by altering the floor soil?

Here is how it’ll work-

  • Choose a soil with better water holding capability
  • Make a pathway or floor with this dirt
  • Produce a Huge area of water surface

As a result, your grow tent or area will observe a growth in RH.

As this new soil must hold water in a substantial amount we have to choose carefully. We know that in case of holding water-


But utilizing a totally Clay based flooring isn’t a good idea. You don’t want your grow-place to become a tacky swamp. So, use a mixture of Clay and Slit with this method.

Your grow place may have plants in developing trays or in soils.

If your plants are on soil, on the floor then this becomes somewhat complex. In cases like this, you do not have to modify the entire growing medium (dirt ). Just offer the grow put a canning flooring with your soil mix.

Create your own Propagation Set-up

Here the trick is to increase the RH by yanking a cool mist in your grow tent.

With this approach, you want an Adjustable extractor + Built-in thermostat.

Now, for the installing part,

Start off by placing a bucket of water, on top of your grow tent. This water will be hauled into your humidifier through a hosepipe.

Shortly, you’ll see a cool mist entering into your grow tent.

Buy a humidifier and eliminate all this humidifying mess.

If you already have one then be sure its dial is in between 50% to 65 percent. If your humidifier has a humidistat, then you certainly do not have to think about turning it off.

However, if it does not have one then you’ve got to be mindful. If a humidifier runs continuously in a restricted area, then it will increase the RH into an extreme degree. Therefore, your grow plants will endure extreme consequences.

So, get a good humidifier or use your grow space humidity meter to examine RH degree timely.

Special Scenarios

We’ve talked about increasing the humidity in three simple stages. First trying out the free procedures, then through low budget hacks and then through the expensive yet effective techniques.

Now, we will suggest to you what to do in special scenarios. These tips include season specific suggestions and growth-stage specific suggestions.

We will discuss which humidity degree is best for which situation and how to get those.

Raising Humidity in Different Seasons

Humidity level does not remain the same throughout all the seasons. So, we will result in season specific facts about raising your increase kayak humidity level.

Summer: In summer the humidity is quite high. So, you might not require extreme methods for this. A couple of hacks would be OK.

Just make sure your grow-place temperature stays between 18-22 degree Celsius or 64-71-degree Fahrenheit. The humidity will adjust on its own.

Start implementing the initial stage.

Use an extra air conditioner or a bigger one if the temperature raised too large.

Fall: In fall the temperature gets cooler every day. If you become aware of your increase kayak humidity level is falling from the Fall, then go through the first phase.

If the first phase does not work properly then begin implementing the 2nd stage methods one by one.

Just continue the RH and temperature in line with your grow point.

If you’re not prepared, then one winter can bring your plants down.

Therefore, during winter be ready to execute even the 3rd stage methods. You may also require low temperature regaining during winter.

Spring: From the spring, both RH and temperature start climbing. Consequently, if your grow room humidity level drops during this time, then proceed through the phases again.

There isn’t any supreme group of processes specified for this particular year.

Raising Humidity in Different Grow-stages


Don’t follow blindly the ordinary RH and temperature degree for your grow-plants all around the year.

Plants require different humidity levels and temperature levels during different grow stages. The daytime and nighttime humidity at the grow space are distinct.

So, let us have a glance at flawless grow-room humidity percent for various growing stages.

We think this chart makes everything clear. So, you can raise your grow place RH degree targeting the limitation of this chart.

Just like before, assess how much RH you’ve managed to increase after using each procedure.

For instance, let’s say you find that during the vegetation stage, your grow tent RH reaches 30%.

After viewing the RH deficiency you have used the Wet towel hanging procedure. After some time, you see this attracted your RH to 40 percent. So, now you require help from another method. This time, you utilize the water tray method.

Following a day or two, you find out that your RH reaches 55%.

Therefore, if one method does not work then combine the following method.

But in case you’re RH raises more than the targeted level, then you have to stop using the previous method and use another strategy.

Neither too High too Low

To find the best output, you must maintain the humidity level in a sweet spot.

If you supply too much humidity, then plants will confront outside problems.

Thus, let’s explore 2 scenarios-

Too High Humidity Kills

Too high humidity will result in grow room condensation. Consequently, your grow tent or room-

  • Will create the best environment for germs and mold growth
  • Will Acquire bud rot or botrytis to your flowering plants
  • Will have the pest and disease threat level in a maximum
  • Will suffocate your increase crops
  • Will decrease the efficiency of your plants’ nutrient intake

Too large humidity will reduce your return if not ruin your crops fully.

So, while increasing the humidity level in your grow tent, be cautious and don’t overdo. Lowering humidity in mature tent is a must if RH goes higher than average.

Too Low Humidity Kills Too

When the humidity is too low in mature room that isn’t great for grow plants in any way.

What the indications of low humidity are in grow room?

There are 3 outcomes of reduced humidity in mature tents-

Your mature plant will draw water excessively from the increase medium. Because of this, your plant will shut up its stomata and endure expansion stop.

As mentioned earlier, due to low RH, your crops begin taking too much water through its roots. With increased water intake, your crops start taking an increased quantity of nutrients. This excess nutrient is actually bad for plants. Because of this, you’ll notice nutrient burn the leaves.

Your crops will get weak and with time they may die due to low humidity level.

Getting scared of the high humidity level, do not allow the RH drop excessively.

Don’t Miss the Security

We’ve laid out several methods in three phases. The majority of these approaches are DIY methods. So, it’s highly advised that you keep some security measures when using those. If not, a slight injury may lead to severe penalties.

Therefore, here are some safety measures that you should keep in your mind –

Whilst eliminating fluorescent lighting, check if your plants are getting enough light. Or else this could be a bad trade-off.

Whilst combining big plants with small ones, make certain that none of your crops are at the flowering stage. You might wind up affecting your grow plant pollination

While hanging wet towels, ensure that you’re not covering light sources.

Whilst establishing your own propagation setup, be extra careful with the electric work. Handling water and electricity at precisely the exact same time is really dangerous.

Whilst using new dirt as the flooring, use gloves. Additionally, following the new soil, be careful while stepping into your grow tent. 1 slip and you might fall back on your face.

Whilst using water-based methods, keep tabs on how much water you’re using. You don’t need to have busted over water bills.

Keep electric lines and water sources far from each other. To be more specific, do your wiring perfectly.

Raising humidity of a grow tent is a tough job. However, it’ll turn into a good deal harder if you miss out any important safety measure and wind up hurting yourself.


Query: What is Vapor Pressure Deficit (VPD)?

Answer: VPD or Vapor Pressure Deficit is the gap between AVP and SVP.

Question: What’s the difference between a humidifier and a vaporizer?

Answer: On the flip side, vaporizers heat water up and release steam. Use a humidifier in a grow area.

Query: Will adding salt be helpful?

Answer: Adding salt at a humidifier won’t be useful as it sprays water.

Bottom Line

It’s been quite a journey. We hope that by now you’ve become the ‘Three-Eyed Raven’ of increasing humidity in grow tent.

Without proper care, your mature crops won’t cover you back properly. So, don’t allow your plants suffer from reduced humidity.

We’ve revealed the answers of –

  • How to get up the humidity in grow tent?
  • How to govern humidity in mature tent?

Now it’s up to you to find the perfect method to raise the warmth in grow tent.

Follow this principle and your grow tent or grow room humidity will get to the sweet spot in no time.

We will be happy to hear your thoughts

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