Thermo- and hygrometers

Temperature is very important in growing plants if it is too cold then the plants will not grow and if it is too hot then there will be too much evaporation of liquid which will cause the nutrient salts to concentrate in the nutrient solution and again the plants will not grow, rather they will be damaged,The hygrometer will show the humidity level: if the air is dry it is bad and if it is too humid it is bad again because then various mould fungi and bad bacilli will start to grow.