Macronutrients (such as $\text{NH}_4\text{NO}_3$, $\text{KNO}_3$, and $\text{CaCl}_2 \cdot 2\text{H}_2\text{O}$) are added in gram or high-milligram quantities per liter, whereas micronutrients and vitamins are added in microgram or low-milligram quantities.