How Do You Heat a Grow Tent [It’s Easier Than You Think]
One of the issues with growing a healthy plant indoors (in a grow tent) is trying to get the area warm enough so that your plant(s) will flourish. There are many ways to do this, sometimes you just need to be a bit creative in your approach. Your marijuana plants will respond better if you ensure a consistent growing temperature for them.
A grow tent can be heated by using a floor space heater or a hanging heater inside the grow tent. A grow tent can also be heated by adjusting the temperature outside of the tent. Some types of lighting will heat your grow tent as well by the heat that the bulbs generate.
Surprisingly, there are probably more ways to heat a grow tent than you might think. In this article, we will explore different options and tips for you to heat the tent in a way that suits you best. The size of the marijuana grow tent will help you decide which is best for heating it. Some ways might be best for a smaller area whereas others would be better in a much larger space.
**Want to cut right to the chase? Check out this Oil filled Radiator Heater on Amazon that I highly recommend.**
How to Increase Temperature in a Grow Tent
There are so many ways to get some heat in your grow tent. Let’s dive right into how…
Heating a smaller grow tent
- Using an aquarium heater in a 5 gallon pail. I like this idea for a room that is smaller than 4’ by 4’ for floor space. What you do is fill up a 5 gallon with water and then place an aquarium heater in the water. Plug in the heater. The heater will work to keep the water warm and by default it will help to warm up the grow area. This method will also add humidity to the space, which your plant will want.
- Sometimes just having a grow tent near an outside heat source is all you need to keep the temperature up. The tent can be placed near a furnace or duct work that has heat running through. This might not work as well in the summer months if an A/C unit is running.
- If you have a location that has south exposure with sun shining in a window that could provide you with enough heat inside of the tent as the sun warms it up every day.
- Insulating the outside of the tent with fiberglass insulation or a Styrofoam insulation will help to keep temperatures consistent and will aid in your grow tent’s warm up as well.
- If you want to have more control over the heat in your small grow tent I recommend using a small space heater. There are literally hundreds of them on the market. Make sure to purchase one specifically made for small spaces. Honeywell makes a nice space heater that throws heat 360 degrees. It has a thermostat as well so you can ensure your grow tent stays at a constant temperature. Heating a Larger Grow Tent
Heating a larger grow tent will be basically the same as trying to heat a smaller tent. The one thing I wouldn’t try in the larger tent that would work in the smaller one is the aquarium heater in the pail of water trick. A larger tent is just too big for this to be effective.
- Using a space heater is almost a must when your tent is quite large and you have a good size crop growing.
- An oil filled radiator is an even better idea than using a space heater for larger tents. Why? Because a space heater is blowing hot air into the space. This could potentially dry out plants to quickly or burn leaves if they get to close. An oil filled radiator heats up and the heat radiates from the radiator. This means the room gets warm with hot air blowing on the plants. An excellent choice is the DeLonghi model linked above.
- Make sure to have an oscillating fan running in your grow tent to help distribute the heat around the plants. Otherwise, one side of the room will be much warmer than the other.
What Temperature Should Grow Tent be?
The ideal temperature to maximize your plants growth potential is between 20 degrees Celsius (68 Fahrenheit) and 28 degrees Celsius (82 Fahrenheit). Temperature can definitely fluctuate without much (or any) damage to your crop. It is the extended temperatures of too cold or too hot that will stunt or kill your marijuana. Don’t let the inside of the tent get any lower than 20 degrees Celsius (68 Fahrenheit) and definitely no higher than 31 degrees Celsius (87.8 Fahrenheit).
If the tent gets to these temperatures, make sure to remedy the situation as soon as possible. Even though space heaters and oil radiant heaters have thermostats on them, it is a very good idea to have a separate thermostat in the room, placed on the opposite side of the room.
You can expect the area where the heater is to get hotter when it is first running and the heat hasn’t spread around the room yet. So, having a thermostat close to the heater might give false readings.
For a reliable thermometer with the added bonus of a humidity gauge I would go for the Thermopro Digital Hygrometer. It is very affordable and easy to use.
Best Temperature for Flowering Stage
The flowering stage of growing marijuana is where all the magic happens. The plant starts to give off its unmistakable scent and the buds start growing big and large, if you have the temperature right.
The best temperature for the marijuana plants flowering stage might differ slightly from species to species, however, there is a general rule of thumb for getting buds to grow. When marijuana is grown seasonally outdoors the flowering stage will occur in the late summer and fall when the temperatures are cooling off a bit.
This means having your grow room at the lower end of the temp range of 20 degrees Celsius and 28 degrees Celsius for flowering to begin. I generally like my plants somewhere between 20 and 24 degrees Celsius for the flowering/budding stage.
Heating the Grow Tent with Lights
As mentioned at the beginning of this article, some lights will produce heat. You will want to take this into consideration when planning your grow tent. Whether you use HPS, compact Fluorescent’s or LED they will all produce some heat. LED obviously don’t throw nearly as much heat as HPS.
Be wary that hot lighting could burn the tops of your plants. Make sure the lights are a safe distance from the marijuana. You will have to adjust the height of the lighting as the plants grow.
How to Keep Temperature Down in Grow Tent
If you are having troubles with the grow room temperature being too high for extended periods of time then keep reading…
The problem with enclosed spaces is sometimes they can heat up to much if they don’t have any way to vent the air out of the grow room/tent. If you are using a commercially made grow tent that you purchased from a supplier that sells them for you to grow plants in then there should be a location specifically for ducting.
You can purchase inline duct that comes with a fan built-in. This ducting will fit perfectly in the ventilation hole when installed correctly. The heat will be sucked out of the tent so as not to overheat.
Tip of the Day
If you are using a space heater or any other item (like a fan) in the tent that has an LED light on it, don’t leave it on all the time. If the plants don’t get complete darkness when the lights are off then the plants could turn into hermaphrodites. If that happens, your buds won’t be as potent with the seeds growing. The buds will also be a bit harsh when smoking.
The way to fix this is to cover all LED power lights with some electrical tape. This will give the room complete darkness. Just make sure you aren’t sneaking a peak when it is dark time for the plants.
Seedling Mats are another Option to Heat Marijuana
Seedling mats are supposed to be used to start seeds growing. It’s definitely not a bad idea to heat the roots and soil of a growing pot plant. All you need to do is lay a seedling mat under a plant pot and turn it on. They never go over specified temperature. They usually run around -12 degrees Celsius (10 Fahrenheit) to -6 degrees Celsius (20 Fahrenheit)
This Vivosun 20” x 20” mat is an excellent option and it is reasonably priced as well. You could sit a large pot on top of this mat easily. There are also many other sizes to choose from so you can make sure to have a seedling heat mat under all your marijuana plants.
Conclusion
Now that you have read this article, you should have a good idea on how to heat your grow tent. I have provided you with some excellent options. Out of all of them I prefer the space heater.
Just remember that you might want to ventilate the room as well. This is a good idea not only for dispersing heat but for clearing out the smell of the weed.
You can also hook up a charcoal filtration system to clean out the scent. To find out more on whether your marijuana plants will smell or not, check out this article.
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