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Quick 10 Steps of How to Cool a Grow Tent in The Summer: Indoor Gardening Hacks

If you’re here, then you’re probably wondering how to cool a grow tent, right? Your soil is constantly going dry because water is evaporating too fast, pot plants are wilting at a rapid pace, and the temp in your tent is super high.

Needless to say, these are problems that a lot of people face when they’re using a grow tent to grow their plants. Therefore, you need to find a way to cool things down in there if you want your plants to grow well.

The problem is, how do you cool down grow tent? If that’s what you’ve been wondering lately, then you’re exactly where you need to be right now.

But before we go on any further, let’s find out what a grow tent is first.

What’s a Grow Tent?

A grow tent can be used again and can be easily moved. It’s manufactured with solid canvas exteriors, and it almost always has a reflective material used inside so that it can optimize the grow lights inside.

Grow tents also has this enclosed area that also has installed grow lights in it so as to properly take care of any hydroponic garden indoors.

This fabric box that’s lined with heat and light reflective materials and equipped with ventilation and light is very popular in the marijuana growing industry.

With that said, it can still be used to grow several types of plants, and all this can be done indoors all year round.

When gardening outdoors, the weather will dictate to you how things should go. On the other hand, with a grow tent, that won’t be the case.

What’s the Suggested Temperature for Grow Tent?

The temperature in your grow tent should ideally be around 70-80 degrees Fahrenheit in the daytime and around 50-60 degrees at night.

You can use a min/max thermometer/hygrometer to measure both the humidity and temperature in the ten.

Why Temperatures Rise Inside a Grow Tent?

If you haven’t built your own grow room just yet, then you can still learn a lot from this segment to help you avoid some certain heating complications in the future.

However, if you’ve already built your space, then you might be experiencing some trouble with high temperatures.

Anyway, let’s take a look at the following reasons why this is happening:

# Improper Ventilation

Apart from sunlight, what else do you think mother nature is providing plants with? If you guessed natural airflow, then you’re absolutely right. When it comes to indoor growing, natural airflow is typically termed as ventilation.

Your plants will be living in a lot of discomforts if your grow tent doesn’t have proper ventilation systems, and high temperature is one of those discomforts they’re bound to experience.

# Too Many Heat Producers

In a grow tent, your lighting will be one of the greatest heat sources. However, they aren’t the only things in the tent that do this. Other items that can produce heat inside the grow space include large pumps, light ballasts, etc.

# Not-So-Insulated Locations

If you’ve been growing plants indoors for a while, you’ll have noticed how important proper insulation happens to be. Always keep in mind proper insulation will help keep high temperatures at bay.

Easy 10 Ways of How To Cool a Grow Tent

Battling the heat inside a grow tent is something that’s common to most indoor growers. Surprisingly, however, this issue can be solved in several different ways, some of which are as follows:

01. Installing an Air Conditioning Unit

Installing an AC is crucial as this can effectively reduce heat, especially during the summer.

Therefore, keeping air conditioners around will help you deal with the heat that comes from the natural surroundings as well as the heat that’s emitted from the pumps, lights, and other electronics inside the tent.

However, before you get on, consider the size of your grow tent first as the AC might not be able to cool the entire area if it’s too small.

Also, keep in mind the seasonal outdoor temperatures that might affect the efficiency of your airconditioning system.

02. Using Carbon Dioxide

This might sound pretty easy, but it actually isn’t. Utilizing this needs practice since this will only work when the suggested temperatures of the grown tent go beyond what’s optimal.

Back to basic biology, we know that CO2 is vital for plant photosynthesis. This means that when you increase carbon dioxide levels in your grow room, there’ll be a spike.

This will help increase plant performance, thereby allowing you to maintain stable functions even during hot conditions.

03. Installing a Water-Cooled Lighting system

Unlike air-cooled lighting, which we’ll talk about next, water-cooled lighting happens to be way more efficient.

In fact, you really have to use an AC unit anymore with this unless suggested.

If you use this technique to cool your grow tents, you’ll need to use a water pump and a reservoir.

Moreover, you have to consider the size of the reservoir and might even need to buy some water chillers as well.

04. Opting for Air-Cooled Lighting

This cooling mechanism is relatively easy to use, especially when compared to the previous two techniques we highlighted above.

This cooling technique uses extraction fans to pass air over the lamps in the tent then eliminates the warm air inside the tent using acoustic/insulated or aluminum ducting.

The insulated ducting systems are way better than the aluminum ones because they do a lot more cooling compared to the aluminum options. In short, the air-cooled lights have glass bottoms that help create air-fitted channels.

The cool air is released via these channels as well as over the lamps to reduce heat. 

05. Ensuring Proper Room Insulation

An insulated space can help manage the temperature of your grows room overall. This is because they won’t be affected by the weather outside.

In some scenarios, the lighting you have in the tent is what might be causing these dangerous heat spikes.

However, in a lot of cases, it could be something as simple as the lack of proper insulation, especially if your grow tents are situated directly under hot roofs.

Keep in mind that underground insulation systems are often way cooler due to the fact that natural insulation is provided by the soil.

Therefore, if you want a cool grow tent, then you may want to strongly consider properly insulating your grow space.

06. Using Reservoir Chillers

If you’re thinking about indoor gardening, then you’ll definitely need to strongly consider having reservoir chillers because they’ll help you effectively manage the temperature in your grow tent.

By now, you know how high heat can greatly affect both the growth and health of your plants.

If you plan to get a chiller, this is a great move as this will significantly help reduce the heat, thus making the room reach that optimal temp fast.

Here’s a short video that will guide you on how you can install a chiller into your system:

How to Cool a Grow Tent Naturally (DIY)

Fortunately, it’s not that hard to cool down you grow tent naturally. In fact, you can do it all by yourself. Here’s how:

07. Structure Your Grow Tent

An overcrowded grow tent is not an ideal situation you want to have. Every grow room has a certain number of plants it can effectively house.

Housing too many plants can give rise to several problems, and experiencing high-temperatures in the tent will be just but one of these issues.

If you want to help your plants fight the stress that comes from high heat temperatures, a fantastic idea would be to grow them in smart pots.

These are known to help aid surge evaporation, thus helping decrease the chances of the room overheating. It also provides O2 from the sides which will help keep your plants healthy as well.

Another smart pot trick that’ll help cool your grow tent down is using Coco air. The plants in a grow room using this method will be able to resist heat very well.

08. Optimize Your Lights

Lighting is typically to blame when you start experiencing those dangerous heat spikes.

There are certain scenarios where your lighting can start acting a lot like heat sources instead of acting as light sources.

A few good examples include:

  • When plants are mature and the lights are lowered
  • Low-quality lighting emitting excessive heat
  • Lack of proper airflow between plant canopy and lights
  • Keeping the lights on when it’s not necessary.

If you want to lessen your lights’ heat impact on the plants, you want to consider the following:

  • Raise the lights as this will prevent heat from your lights directly impacting your plants. Raising your lights by around eight to ten inches can act as a temporary measure.
  • Install light movers since uneven illumination and hot spots can be created when your lights are put in constant places. Try making use of motorized movers in your grow tent to keep your lights in motion. These devices will transport your light sources back and forth, and you can even use curved tracks if you like. These devices help distribute both the light and heat evenly across the entire grow tent. It will also help reduce the hotspot numbers and canopy overgrowth complications as well.
  • Turn on the lights only during the night.

Ambient temperatures are usually a little cooler at night when compared to what’s experienced during the day.

Indoor growers, especially the ones residing in hot climates, should avoid running their lights during the day.

It’s because the temps by then are already a bit higher. Instead, try to run your lights only during nighttime since this will help keep you grow tent’s overall temperature under control.

09. Maintain Proper Ventilation

Before we move on, keep in mind that you need proper ventilation in your to grow tent. Many people usually think it’s not necessary, but that’s a mistake to think that way.

Anyway, air exchange or ventilation is arguably one of the most important factors that directly affect the temperature of your grow room.

Lack of proper ventilation will result in constant temperature increases because the heat that’s generated inside the tent will just keep on rising.

So, why aim to have the great circulation of air in your grow tents? Well, for starters, proper ventilation helps provide your plants with the same airflow they can get if they’re grown outside.

To have optimal ventilation systems, you should first make sure your grow tent has regulated airflow.

This can be made possible with the use of either an extractor fan or an oscillating fan.

The former is designed to blow air from above, around, and under your plants, while the latter brings in new, fresh air from outside.

Aside from that, you need to maximize the effectiveness of these fans. In the coolest spots nearby, begin by placing input ductwork.

Next, invest in automated controllers that’ll help raise and lower fan speeds based on how hot the tent is at any given time.

10. Cool Down Using Ice Bottles

Who would’ve thought an ice bottle could help cool anything other than your face? Well, having an ice bottle in your grow tent can help drastically cool down the temperature inside, and the whole process is pretty simple too.

All you need to do is fill a two-liter bottle with water then put it in your fridge until the water freezes.

Once the water has completely frozen, place the water bottle into the nutrient tank and watch it do its magic. It will help cool down the reservoir very fast.

However, you should only use this method of cooling as a last option or alternative because if the temp can’t be regulated by the bottle, then you’ll eventually need to use a reservoir chiller.

How to Keep Your Grow Tent Cool in the Summer?

During summertime, your tent’s temp will be occasionally rising way above 80 degrees, and you don’t want this.

Here’s how you can keep the grow room cool during this time.

Lower Your Plant’s Nutrient Strength

When the temperature is high in the tent, your plants will start to absorb a lot more water. That, in turn, will also force them to absorb way more nutrients as well. This can give rise to toxicity complications.

Diluting the nutrient solution in the grow room by twenty percent using clean and fresh water will help reduce a lot of stress.

Furthermore, you can also use an air stone or air pump to keep everything well agitated.

  • Seal It Up

Ventilating a grow tent won’t always work for all indoor growers, especially those that reside in very hot climates.

These growers typically seal their tents, use an air conditioner for cooling, and add carbon dioxide via a tank or generator attached to a regulator.

You should also keep in mind that plants have the ability to tolerate high temperatures in conditions and environments that have elevated carbon dioxide levels (up to 1300 PPMs) which is approximately 4 times the normal atmospheric levels.

  • Increase Nutrient Additives

Increasing silica levels will help your plants endure the hot summer season by strengthening their cell walls.

General hydroponics have Armor-Si, a fantastic silica supplement that’ll help coat the root zones of your plants with beneficial fungi and bacteria which makes it extremely hard for pathogenic organisms to colonize these regions.

Sub-Culture B and Sub-Culture M are also two other very good supplements form General Hydroponics you may want to check out as well.

If all else fails, you want to move your grow tent to a location that’s better insulated, preferably underground where you can use natural insulation.

Lastly, always keep in mind that temp management is particularly important during flowering, ripening, and fruiting annuals. During these periods, your plants will need cooler fall conditions.

How to Reduce the Heat in a Grow Tent?

  • Increase Air Exchange

You can do this by cranking up the extraction and input fans if you want to bring more fresh, cool air in and eliminate more stale, hot air from the grow tent.

Thermostatically controlled fan speed controllers will help you achieve this automatically without you having to constantly check on them.

Having to use manually turn dials can get quite cumbersome. Also, make sure to get air into the grow tent from the coolest places you can find.

Some indoor growers like to use airconditioning systems to cool this input air, especially when the summertime comes rolling in.

  • Chill Your Nutrients

Most plants have the ability to tolerate extremely high air temperatures, as mentioned earlier, up to 100 degrees Fahrenheit or even more.

If you chill your nutrients to about 65 degrees or so, this could help keep the grow room cool. You can employ the use of a pump to help you circulate the nutrient solutions through an aquarium chiller.


To summarize everything that has been highlighted in this article, cooling a grow tent is an issue many indoor growers face all over the world, especially when it’s really hot outside.

The effects of a high-temperature grow room can be devastating because it can cause the growth of your plants to drastically slow down.

Not only that, but it can also increase moisture loss, affect seed germination, and hamper plant growth as well.

We can’t overemphasize how important it is to keep the temperature in your grow tent at an optimal level. Excess heat in your grow tent is something you definitely don’t want.

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