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How to Make a Hydroponic Nutrient Solution Using Epsom Salt

By Ma Wen Jie ; Updated September 21, 2017

Hydroponics is a method of growing plants without soil in a bath of water and nutrients. The plant's roots absorb water and nutrients from the hydroponic solution. Although there are many commercially available solutions, you can make your own solution using Epsom salts and other chemicals. For nutrients that your plants will need in very small quantities, mix two bottles of micro-nutrient solution that you will then add to your overall solution.

Fill a 10-gallon container with about a gallon of water. Begin mixing the nutrients in a gallon; you will add 9 gallons of water later.

Add 2 level teaspoons of ammonium phosphate. This will add nitrogen and phosphorus to your nutrient solution.

Add 4 teaspoons of potassium nitrate to the container. This will add potassium and nitrogen to your nutrient solution.

Add 4-1/2 teaspoons of calcium nitrate to the container. This will add calcium and nitrogen to the nutrient solution.

Add 4 teaspoons of magnesium sulfate, or Epsom salts, to the solution. This will add magnesium and sulfur to your nutrient solution.

Mix 1-1/4 teaspoons of boric acid and 1/10 of a teaspoon of magnesium chloride to a quart of water. Add 1/2 cup of this micro-nutrient solution to your 10-gallon container.

Mix 1/2 teaspoon of chelated iron in a quart of water. Add 1-3/5 cup of this micro-nutrient solution to a 10-gallon container.

Thoroughly mix all of the ingredients in the initial gallon of water. Add another gallon and continue mixing.

Add water a gallon at a time mixing between gallons until you have added a total of 10 gallons of water to your container.


Things You Will Need

  • Hydroponic system
  • 10-gallon container
  • Ammonium phosphate
  • Potassium nitrate
  • Calcium nitrate
  • Epsom salts
  • Quart jars
  • Boric acid
  • Magnesium chloride
  • Chelated iron


  • The nutrient solution should be good for 10 to 14 days of hydroponics. After 10 to 14 days, mix a new batch and replace the old solution.

About the Author


Although he grew up in Latin America, Mr. Ma is a writer based in Denver. He has been writing since 1987 and has written for NPR, AP, Boeing, Ford New Holland, Microsoft, RAHCO International, Umax Data Systems and other manufacturers in Taiwan. He studied creative writing at Mankato State University in Minnesota. He speaks fluent Mandarin Chinese, English and reads Spanish.