Hoagland’s Solutions

Hoagland’s Solutions

Hoagland had two solutions, #1 has all nitrate; #2 had some ammonium, which kept the pH lower. Most people now use a modified Hoagland solution because the originals used iron tartrate instead of a chelate.

Miracle-Gro is not formulated for hydroponics so will kill plants if used in solution culture.

Hoagland solution #1 (per liter of nutrient solution):

  • 5 ml of 1 M potassium nitrate
  • 5 ml of 1 M calcium nitrate
  • 1 ml of 1 M monopotassium phosphate
  • 2 ml of 1 M magnesium sulfate
  • 1 ml of micronutrient stock solution (see recipe below)
  • 1 to 5 ml of 1000 mg/liter iron from iron chelate (Fe-EDTA, Fe DTPA, or Fe-EDDHA)

Hoagland Solution #2 (per liter of nutrient solution):

  • 6 ml of 1 M potassium nitrate
  • 4 ml of 1 M calcium nitrate
  • 1 ml of 1 M monoammonium phosphate
  • 2 ml of 1 M magnesium sulfate
  • 1 ml of micronutrient stock solution
  • 1 to 5 ml of iron chelate stock solution as for #1
Micronutrient stock solution per liter:
  • 2.86 g boric acid
  • 1.81 g manganese chloride – 4 hydrate
  • 0.22 g zinc sulfate – 7 hydrate
  • 0.08 g copper sulfate – 5 hydrate
  • 0.02 g 85% molybdic acid
When diluted 1:1000 the micronutrient stock solution provides the following in mg/liter:
  • Boron 0.5
  • Manganese 0.5
  • Zinc 0.05
  • Copper 0.02
  • Molybdenum 0.01

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