Air humidity – Hydroponics

Air humidity – This is a value that characterizes the content of water vapor in the Earth’s atmosphere, or in the growing space in particular cases. Different units are used to measure moisture. The main modes of expression are absolute humidity and relative humidity.

• Absolute air humidity Is the mass of water vapor contained in 1 m³ of air. In other words, it is the density of water vapor in the air. Measured in g / m³.
• Relative humidity Is the ratio of its current absolute humidity to the maximum absolute humidity at a given temperature. Measured as a percentage. Measured with a hygrometer.

When growing plants, the relative humidity is usually determined. This is a very convenient value, but not without flaws. The higher the air temperature, the more moisture it can hold. This means that as the temperature rises, the relative humidity will drop, although the actual moisture content may not change.

Temperature t, °C
−30
−20
−10
0
10
20
30
40
50
60
70
80
90
100
Максимальная абсолютная влажность f_Max, (г/м³)
0,29
0,81
2,1
4,8
9,4
17,3
30,4
51,1
83,0
130
198
293
423
598

Moisture for healthy plant development

For both soil and hydroponic cultivation, there are general guidelines for humidity levels.

• In the initial stages of growing (seedlings or cuttings), it is necessary to maintain a high relative humidity – 80% and more.
• For mostly vegetative growth, plants prefer a relative humidity of about 55-70%.
• And finally, when the plants are blooming and bearing fruit, the humidity should be within 40-55%… This will help them focus on the production of buds, flowers, and fruits.

These recommendations show that as plants develop, their moisture requirement tends to decrease. However, the larger and more abundant your indoor plants are, the more moisture they evaporate, and the more they affect the humidity of your growing space! This is a kind of conflict of needs. This is why we ventilate our growing rooms or use air conditioners and dehumidifiers.

Ways to increase humidity

The easiest way to maintain a constant humidity level is to ventilate the grow room. If the outside humidity level drops below 40%, you may need to use a humidifier. For small rooms and grow boxes, a household humidifier will be more than sufficient.

Ways to lower humidity

In cold weather, many cover up the ventilation to conserve heat in the room. Transpiration of plants creates excess moisture, therefore, an air dehumidifier may be needed.

Literature

1. William Texier. Hydroponics for everyone. All about home gardening. – M .: HydroScope, 2013 .– 296 p. – ISBN 978-2-84594-089-5.