Temperature
 Used for air temperature (day/night), solution temperature, and substrate temperature measurements in your grow environment. 
Volume
 Used for pot sizes, watering volumes, and any other liquid measurements in your grow setup. 
Weight
 Used for measuring harvest yields, nutrient amounts, and other weight-based measurements. 
Length
 Used for plant height, lamp distance to plants, and other linear measurements in your grow space. 
Total Dissolved Solids
 The amount of dissolved minerals, salts, and metals in water. 
Nutrient dosage
 Used for measuring nutrient and supplement dosages.