September 06, 2021
If you’ve yet to build your grow space, that’s cool. But in case you already have one, then a high temperature might be troubling you badly. So, before proceeding further, take a look at the most possible reasons for it-
Take a look at the outdoor garden or the local park. What’re the other things that mother nature is providing them apart from the sunlight? You’re right, it’s the natural air flow. Which is termed as Ventilation in case of indoor growing. Lack of proper ventilation comes with several discomforts for the plants. And a higher temperature is the #1 of them.
Lights are the greatest heat source in a grow room. But there are items that emit heat that circulates around the space. Examples- Light Ballasts, Large Pumps, etc.
I’ve been a grower for past 2 years. And from the very beginning, I grew plants in my basement. Growing in such an insulated area helped me to get at least 5°F less temperature than the same setup planted anywhere in the house.
And when the plants get overheated from one or many of these reasons, that begin to show signs of stress. Which results in a low yield of flower or fruit. Go through the next sections of the article, if you’ve to know some real-time ways to beat the heat in your grow space
It seems like the majority of indoor gardeners struggle with high temperature, so let’s look at ways you can decrease your temperature.
If high temperatures are wrecking your indoor garden, there is no better way to quickly bring the temperature down than an air conditioner. You can easily place them either in the marijuana grow tent or some models allow you to have them outside the tent while ducting the cool air in.
For more information on air conditioners, read our guide on choosing and sizing the best one for your growing space.
Many hydroponic setups keep the reservoir outside of the tent as dangerous algae can grow in the water when the temperature rises above 70 degrees. However, if you’re using a Deep Water Culture (DWC) system then this means your plants’ roots are directly sitting in the reservoir, so it will be in the tent. Reservoir chillers are crucial in DWC and other hydro setups.
They give you some of the best looking, highest yielding, and tastiest plants, but everyone agrees that their one big downfall is the heat they generate. If you’re using HID grow light like high pressure sodium or metal halide bulbs, you need to prepare for ways to decrease temperatures.
Air Cooled Lighting — Air-Cooled lights work by using extraction fans to pass air continuously over the lamps and then exhausting this warm air out of your grow room via aluminium ducting. If you use acoustic/insulated ducting on the outlet this will help cool your grow room even more.
LED has proven they’re here to stay and the best ones are reducing your grow tent’s heat by at least 40% compared to an HID of equivalent wattage. Most LED users fight will low temperatures during propagation and early veg, as LEDs have to be hung at least far from the plant’s canopy as HIDs. You can run lower wattage LEDs in your grow tent for several reasons. The biggest reason is LEDs produce light in a 120-degree angle directly hitting your canopy unlike the 360-degree angle HIDs and fluorescents which has to be redirected affecting its efficiency. The best LEDs will give you the most lumens/light for the least amount of watts, and this is why they are the “coolest” grow lights currently out there.
These days all good grow rooms and indoor gardeners have hygrometers, but to get a true indication, the more the merrier. Try to have a minimum of three, one up high, one in the middle and one lower down. This will help you to identify cold spikes or heat pockets etc
Some growers prefer lots of little clip fans some like stand fans others have wall mounting or floor fans. Again the more the merrier but diversity is key. For example try to alternate different fans blowing alternately as the wind outside never blows the same way for too long. Fans with oscillation or fans that have a circulating and moving louvre are ideal. If possible try to create a vortex of sort by having a fan in each corner, each one face the other helping to create a circulating vacuum of air.
Another strong catalyst behind your grow room’s temperature is a low level of humidity. As you know, low humidity causes a rise in temperature. And vice versa.
To beat with a high temperature, increase the relative humidity of the grow space. That will help plants to do exhale water vapor through leaves, resulting in coolness.
Now, how much increment would be needed? Or how to keep your grow tent cool with that?
A fine rule of thumb is to keep the humidity 60% or more for young plants, and 40% or more for mature, flowering plants.