In hydroponics, plants are grown in a solution of essential nutrients. Plants require these nutrients to thrive at optimal levels. Nutrients and water are taken up through the plants’ roots in hydroponic gardening systems. Adjustments to nutrient levels need to be performed throughout the plant’s life in order to ensure there’s neither nutrient excess or deficiency.

Here is a list of the 16 essential nutrients plants require for healthy growth.


1. Nitrogen (Nitrate or Ammonium are both typically used)
2. Potassium (Potassium Nitrate or Potassium Sulfate are most commonly used. Potassium Chloride is also used)
3. Phosphorous (Phosphates containing Ammonium and Potassium are commonly used. Also, Phosphoric Acid)
4. Calcium (Calcium Nitrate)
5. Magnesium (Magnesium Sulfate)
6. Sulfur (Sulfur is sufficient with the sulfates present in Potassium Sulfate and Magnesium Sulfate)


7.   Iron (Numerous forms are used: Ferrous Sulfate, Ferric Sulfate, Ferric Chloride, Iron Ammonium Sulfate)
8.   Copper (Copper Sulfate)
9.   Zinc (Zinc Sulfate)
10. Chlorine (Chlorine does not usually have to be added to the solution, since it is already present in most water)
11.  Boron (Boric Acid, Solubor, Borax)
12.  Cobalt (Cobalt Nitrate)

Read more about optimal growing conditions in hydroponics.