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Humidity can be a blessing for an indoor plant-growing system. It can, within short periods, become a curse if not well managed. Like temperature, humidity plays a crucial role in determining the quantity and quality of yields in all indoor gardening systems.
When an indoor garden’s humidity becomes too high, it can quickly become a nightmare for growers. This important element is often neglected for many beginner gardeners until problems like bud root and powdery mildew begin to surface.
We hope you have not been frustrated to levels where you regret embarking on this beautiful indoor gardening journey because you could not manage this situation.
This article is the outcome of many months of indoor gardening research on how to lower humidity in grow tent. It explains why high humidity is bad news for your garden and contains both short and long-term solutions that will help lower humid air levels in your indoor plant-growing system.
A Brief Overview of Humidity
This might be somehow technical but easy to understand. Humidity is the water found in vapor form in the air. Another term you will see thrown around is relative humidity. This is air fully loaded with water vapor such that it can no longer hold water.
For optimum plant growth, the relative humidity must be maintained at certain thresholds. If your gardens exceed the recommended humidity levels at any growth stage, the quantity and quality of yields will be affected.
Why is high humidity bad news for your garden?
So, you have been told to maintain high humidity to ensure the optimal growth of your plants. While this is true, very high levels of humidity can cause more damage than good.
Avoid excessive humidity levels to prevent:
- Impeding transpiration in plants
- The outbreak of pests and diseases.
- Creating a suitable breeding ground for molds and bacteria.
- A reduction in plant yield
- Slowing down nutrient uptake
- A reduction of the plant’s capacity to absorb water via the roots
- Reduced absorption of carbon dioxide
- The clogging of plant stomata.
It is therefore important to know effective ways to maintain optimal humidity levels in your grow tent.
What are the optimal humidity levels for a grow tent?
Plants need different humidity levels at various stages of life. This difference is a result of the required level of water in the different growing stages. Maintain the following humidity levels for your plants all the time.
Seedling stage – Rh 70 to 75%
Your plants have only just started growing. They do not have developed roots that can absorb the level of water they require to sustain growth. As such, plants at this stage depend on moisture from the atmosphere.
A grow tent with high humidity is excellent for plants at this stage of development. It is critical to growth and development.
Vegetative Stage – Rh 50 to 70%
Plants have well-developed roots at this stage of development. However, they need to absorb water found in vapor form in the air.
Low humidity levels will result in stunted growth.
Flowering Stage – Rh 40 to 50%
Plants at this stage of development need average humidity levels conducive to flowering. This humidity level will prevent the infestation of mildews and molds on the flowering plants.
Harvesting stage – Rh 45 to 50%
The humidity levels should be at average levels for plants in the harvest stage. This is to prevent the yield from becoming harsh and brittle.
How to lower humidity in grow tent
1. Do not mix young and matured plants
Plants at different growth stages require different humidity levels. As such, do not mix crops in a different stage of life in one grow room.
This is because the growth of matured plants will adversely affect the development of young plants. Matured plants have large stomata; they release a large quantity of water during respiration, increasing humidity in the growing room.
Plants in the vegetative stage will not be affected; others in the growing stage will be negatively affected by the increased humidity levels.
Ensure that all crops in one grow tent are in the same growth stage.
2. Adequate watering
Stop overwatering your crops if you want to record excellent yields from the indoor garden. This is one of the simplest ways to lower high humidity levels in a tent.
When you overwater your plants, they will absorb plenty of water and release the excess to the atmosphere during respiration. This will lead to high levels of humidity in your grow tent.
When the temperature in the growth room rises, excess water will evaporate from the soil into the atmosphere and lead to high humidity levels.
Overwatering also leads to soggy and damp soil that will negatively affect your plant growth.
3. Prevent outside humidity from getting into the grow room and insulate the grow tent
Sometimes high humidity levels in your grow room might be caused by outside sources. Your options for reducing environmental humidity are limited. However, you can set up your grow room in a way that prevents humidity from external sources from affecting your plants.
To do this, invest in an insulator, and have it installed over the grow tent.
Reflectix BP48010 Insulation is one of the best insulators in the market in 20201. It is available on Amazon and has excellent ratings. Check the features, buy and insulate your grow room with it.
4. Use rich soils that drain water easily
The three major types of soils are loam, sandy, and clay — having different water retention capacities. Clay soil absorbs the highest quantity of water and does not drain quickly. Sandy soil has no water holding ability and drains very fast. Loamy soil has water-absorbing and draining characteristics between sandy and clay soil.
Loamy soil is preferred in vegetative farming because of its water-draining characteristics and the ability to retain nutrients.
Do not use clay soil in your grow tent. It will retain water and does not drain easily. The water will eventually evaporate, increasing the relative humidity in the grow room.
Go for loamy soil; it absorbs water, drains moderately, and holds nutrients. However, if you prefer a soil type that drains water easily, go for sandy soil. But remember to monitor the nutrient level.
5. Remove unnecessary water points in the growing tent
Look around the grow tent, are there containers holding water? Remove them. Remove any source of extra water in the grow tent. When temperature rises in the grow tent, water in jars, trays will evaporate, contributing to the relative humidity in the growing tent.
In addition, stagnant water is a potential breeding ground for bacteria and fungi. This can cause an additional problem. Crops become adversely affected by humidity and diseases caused by microbes living in the dirty waters.
Drain stagnant waters and empty water reservoirs. Construct a solid drainage system to rid the grow room of excess water at all times.
Alternatively, if the water supply points can’t be removed, consider covering exposed water surfaces. The goal is to reduce the evaporation of water as much as possible. This is one of the most effective ways on how to lower humidity in grow tent without a dehumidifier.
6. Improve Air Circulation
Ensure your grow room has adequate ventilation. The grow room should be fitted with good exhaust systems to expel humid air when required. Also, your grow room should have a sufficient supply of low humid air all the time.
To accomplish this, create multiple inlet holes in the grow rooms.
To boost air circulation in the grow area, install grow room fans. There are many quiet fans on Amazon. Buy one or two and install over your ventilations.
The size of your grow tent will determine the capacity of the fan to go for. In all, buy a fan having adequate CFM.
7. Install a Dehumidifier
This is the most effective method to lower humidity in a grow tent. A dehumidifier is specially designed to get rid of excess water vapor from the air.
One good thing about a dehumidifying machine is the ability to maintain a constant humidity level in your grow tent.
From our experience, it’s best to place a dehumidifier in the middle of the grow room. Ensure it is a device having an auto shut-off setting.
Dehumidifiers having this feature will dehumidify the grow room, and when a preset level is attained, it auto shut off.
Vremi 22 Pint Dehumidifier is one of the best dehumidifiers in the market. It is energy-efficient; as such, it won’t unnecessarily raise your energy cost. In addition, it is quiet. As such, if your grow tent is indoor, it won’t disturb people living around.
8. Defoliate Your Plants
This is a simple and pocket-friendly method to reduce humidity levels in grow tent. Vegetative plants with large leaves will raise the humidity levels. Cut down these leaves to prevent the humidity from rising above healthy levels.
Monitor the Humidity Level in grow tent
Monitoring humidity levels is not a preventive measure. A hygrometer will help you monitor the overall humidity levels at any point in time.
You will find thermometer-hygrometer combinations in the market. Hanging one in the grow tent means accomplishing two purposes with one device.
The following are excellent examples of thermo-hygrometer devices perfect for monitoring humidity levels in grow tents.
Q: What is the cause of high humidity in grow tents?
As the temperature rises in the grow tent, the more water evaporates, the more humid the grow becomes. The higher the heat, the faster water travels through the air. The more the area it covers, the higher the relative humidity. On the other hand, the lower the temperature, the less humidity.
Q: Can fans lower relative humidity in a grow tent?
Air conditioners are designed to cool the air. Thus, they lower humidity levels. Air conditioners frequently replace hot air with cold air. When paired with a fan can maintain a cool growing environment with a moderate humidity level.
Q: Can I reuse the water from my dehumidifier?
Dehumidifiers are not designed to collect distilled, clean water. If you want to, empty the water as often as it fills up or once a day. You can use this water as a distilled water in small appliances like steam irons or hot water urns.
Q: Why does my dehumidifier not collect water?
Is your dehumidifier placed in a room having a temperature above 65 degrees Fahrenheit? If yes, there might be a fault with the capacitor in the compressor circuit. The compressor’s duty is to circulate refrigerant in the device that removes moisture from the air, collected as water in the bucket.
There is no reason for your plants to be destroyed by high humidity. By applying the simple techniques on how to lower humidity in grow tent, you will be able to effectively create a conducive growing environment for your crops.
For the best results, consider combining one or two techniques above. These simple hacks are inexpensive, effective, and will lower humidity in grow tent.
Of all the methods discussed above, dehumidification is very effective. Thus, if you need a permanent, long-lasting solution, go for this.
It is also important to buy quality equipment. Grow tents, dehumidifiers, or whatever device you will be using in the grow tent should be efficient and long-lasting. The recommendations in this article are top-quality products, click on them, read their features, reviews and make a buying decision.