What it is
A little device that measures temperature (thermometer) and the air's relative humidity (hygrometer). It is the first instrument every indoor grower has.
What relative humidity is
How much water the air holds compared to the maximum it could hold at that temperature. 100 % is fog. Warm air can hold more water: that is why, when the light goes off and the temperature drops, humidity rises on its own.
How to use it right
At the height of the plant tops (that is where it matters), in the shade: if the lamp light hits it, it reads hotter than it really is. Many people save the day's max and min: that way you see what happened overnight or while you were away.
Reference values
Temperature: 20 to 28 °C. Humidity: 65-75 % for seedlings, 50-65 % in veg and 40-50 % in flowering.
▲ Pros
- Comes in the kit
🎮 Practice it in UnderGrow
It comes in the starter kit (it is drawn in the corner). With it you see temp and rh in the panel; if anything goes out of the ideal range for the stage, it is marked in color. By tapping equipment › (on the panel) you see the climate and the equipment.
▶ Play free