Proper control of the environment is the key to successful cultivation, and humidity is one of the biggest factors. If you master it, you will see a huge impact on the overall health of plants. In this article I will explain why humidity plays such a big role and what equipment you need to have constant control.

When water and nutrients are absorbed through the root zone, they are transported upward by xylem cells and distributed to the areas they need. In the end, however, 97% of the fluid taken on board is lost through the stomach-small pores found on leaf surfaces, which facilitate gas exchange for the process of photosynthesis. Plants live in a continuous cycle of fluid collection and loss, and it is therefore essential that the right balance is maintained at all times. To complicate matters further, this balance is not just a product of activity in the plant, but is also dictated by the conditions in the room (or outside).

If the surrounding atmosphere has moisture levels that are too high, then the plants will retain water more easily. If the surrounding atmosphere is too dry, then the plants will overflow (lose water) faster.

As a result, your environment will have a huge impact on the way your plant uses nutrients. When the plants are transpired too much, you will notice that the nutrient solution in your tank becomes more concentrated. This is because the plant has used the water from your nutrient solution and left behind an excess of minerals, raising EU levels. If left for too long, it will inevitably damage the roots, leading to stunted growth and causing irreparable damage to the upper half of the plant.

Conversely, if the humidity in your room is too high, then your plant will have problems absorbing the necessary nutrients. This is because if the plant loses less water through the stomach, then in turn, less nutrient solution will be absorbed by the roots, leading to deficiencies.

In addition, high levels of humidity increase the risk of mold problems such as powdery mildew, a fungal disease that infects plants, slows growth and compromises yields. Botrytis (otherwise known as 'pimple rot') is another fungal pathogen that destroys fruit from the inside out, making it difficult to detect the disease. Only these two diseases can completely erase entire yields and cancel months of work!


So it is quite clear that humidity levels play a huge role in deciding the fate of your indoor garden. Success or failure will depend on reaching your humidity (along with temperature) in optimal regions. If you understand this, you are on the way to achieve bigger and better yields!

So, what are the right humidity levels to strive for? To really improve your environment, you will need to look at VPD (steam pressure deficit) levels, but to keep things nice and simple, we will work with some rough averages, assuming your daily temperatures are around 25 ° C. .

80% for clones

65% during vegetative growth

50% flowering


Achieving an 80% humidity level during the cloning phase is actually quite easy. Store your uprooted cuttings in a propagator and use the adjustable air vents to allow moisture to drain out when needed.

During the vegetative growth the plants are still small in size. To get into the sweet environment of 65%, you may need a little help - and this will appear in the form of a moisturizer.

The ultrasonic humidifier Ventilution is great for amateurs, with a tank of 8 liters and a price of only BGN 175.00. However, since its limit is 0.5L / h, if you have a larger growbox or room for breeding, you could go to the next level with the Ultrasonic Fog Generators with limits of 1.2L / h, 1.5L / h and 2.7L / h . Since they are placed in a separate container, you choose how much water to pour and how long you need to fill it. Check out all our humidifiers - here!


It is important to note that if you use ordinary tap water with your humidifier, it will eventually leave mineral deposits on the surfaces of your equipment and damage it in long-term use. The problem can be solved relatively easily by using water that is filtered and the EC reads zero. Growmax filtration systems are favorites among our customers as well as the Picobello reverse osmosis system.


We wish you a successful growing!