How To Lower Humidity In Grow Tent: An Indoor Grower Should Know

The first time that I built my very own grow tent, I honestly didn’t know how to properly make use of it. One of the most puzzling things I have encountered was how to lower humidity in grow tent.

That also the reason why I decided to really the concept of humidity and how it affects that growth of my plants. Surprisingly, I learned so many, and that is also what I would like to discuss in this article for the benefit of those who are just starting out with indoor gardening.

I decided to write this article to share my knowledge and help you discover the ways of how to lower humidity in grow tent. On top of that, this article also contains additional knowledge that you might need in the future regarding indoor gardening and grow tents.

What You Will Need

How To Lower Humidity In Grow Tent

Like any other task or project, there will be materials that you need to prepare before undertaking this job. Here are the necessary tools that you will need to gather before we start.

  • Dehumidifier - to directly decrease the humidity inside the grow room.

  • Air conditioner - effective way to increase the amount of cool air.

  • Fan - an alternative to an air conditioner to increase air inside the grow tent.

  • Gardening scissors - for trimming excessive leaves on your plants.

Aside from these tools, it is also best that you do some research beforehand about humidity. Having the right knowledge about grow tents, gardening, thermoregulation, and knowing what the right atmosphere is for a grow room makes a whole lot of difference.


Get yourself a humidity monitor for you to have a view of the humidity level inside your tent. There is also an alternative which is a combo meter that tells the temperature and humidity level in one gadget.


Another important thing I did when I was starting out was to familiarize myself to the right level of humidity per stage of my plants’ life cycle. For instance, during the seedling stage, the humidity required 65% to 70% to encourage growth. During the germination stage, the acceptable levels range from 40% to 70%. At the plant’s flowering stage, the humidity level should be at 40% to 50%.

How To Lower Humidity In Grow Tent: The Step-by-step Guide

How To Lower Humidity In Grow Tent

Gathering the materials is just the beginning. The real work comes after which is going through and learning the different ways of how to lower humidity in grow tent. Here are some of them.

  • Make Use Of A Dehumidifier

                One sure way to lower humidity in your grow tent is with the use of a dehumidifier. This tool is specifically designed to eliminate the excess moisture that is present in the air. This is usually attached to a drainage system so you easily get rid of the collected water. This may be not one of the cheapest options, but it does the job effectively.

  • Use An Airconditioner

                   Most people will use an air conditioner to produce cool air. However, this process of giving off cool air has more to it than that. An air conditioning unit makes use of gas and compression that pulls heat out of the atmosphere. Through this process, condensation happens which results in the elimination of moisture in the air and the decrease of humidity. To know how to choose the ideal air conditioning unit for your grow tent.

  • Ventilation Improvement By Adding More Fans

           Another sure way to decrease or lower the humidity inside the grow tent that I discovered is to improve the ventilation system. The grow room or grow tent needs to have adequate airflow to the right humidity level is achieved. You can do this by adding more fans which could be your exhaust or your intake fan. However, it is advisable that you keep your outflow fan bigger compared to the intake fan.

  • Monitor and Remove Stagnant Water

            From all the years I have been doing indoor gardening, I have also noticed that stagnated water adds to the humidity inside the grow tent. This why it is best that you keep a keen eye of any pool of water that might be stuck somewhere around your grow tent. You also need to check the drainage and make sure that it is not clogged. If you spot any stagnant water, immediately get rid of it. 

  • Defoliate Your Plants

                 Believe it or not, the number of leaves that your plant has can also affect the humidity levels inside your grow tent. This is why defoliating is another way that you can use to help reduce humidity in your grow tent. Using garden shears or scissors, you can trim off some of the leaves from your plants which will help decrease humidity.

How To Lower Humidity In Grow Tent

Humidity And Its Affects Plant Growth

​To better understand what humidity is, in simple terms, it is the measurement of how much water vapor is present in the air. This presence of water vapor in the air is a result of several factors inside the grow tent.

One of which is the temperature inside the tent. The presence of humidity is actually not a bad thing in most cases. In fact, this indicates that your plants have sufficient water source for them to grow healthy.

However, the level of humidity inside a grow tent must be monitored and maintained depending on the stage of your plant’s life. Generally, the humidity level inside your grow tent should not go beyond 70%. Otherwise, this might have harsh effects of your plants.

How To Lower Humidity In Grow Tent

Dangers Of High Humidity in a Grow Tent

You must keep in mind that your grow tent needs to be at the right level of humidity in order for your plants to grow healthy. The increase of humidity inside the grow room can have damaging effects on plant development. 

  • High humidity levels encourage the growth of mildew and molds which can be a conducive environment for bacteria and other parasites to grow into.

  • Its prevents transpiration to happen in plants.

  • It causes clogs in the plants’ stomata which reduces the intake of carbon dioxide. As a result, this can cause issues during the process of photosynthesis.

  • It renders the plant roots incapable of absorbing the sufficient amount of water it needs.

How To Lower Humidity In Grow Tent


In summary, maintaining the humidity level inside your grow tent is one of the most important factors you need to learn in order to ensure healthy plant development. You can follow the ways that I have shared to help control and lower humidity in your grow tent when it gets beyond the required level.

Together with that knowledge, I would also advise that you keep on reading and acquiring knowledge about Horticulture and Gardening, Botany, Atmospheric Sciences and other topics that you can use as a reference in order to have a well-maintained grow tent.

Do you find this article helpful? Were you able to learn the different ways on how to lower humidity in grow tent? Can you think of other ideas related to this topic? You are welcome to voice out your opinion about this article. Send your feedback and recommendations by leaving a comment below.

Dan Harris

Hi. I'm Dan Harris. My wife and I started gardening 5 years ago. Neither one of us had any gardening background but we loved the idea of growing our own organic food. Over the years, our garden has almost doubled in size and I’ve learned a lot from my season’s successes and failures. I’ve been excited to share my own beginning knowledge and special skills with all garden lovers.

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