Hesi CalMag – For the perfect mineral balance in your plants

Hesi CalMag provides plants with a targeted supply of calcium and magnesium – two essential nutrients for vigorous growth, stable cell structures and lush green leaves. These important minerals are often lacking, particularly when using soft water, demineralised water or reverse osmosis (RO) water. Hesi CalMag reliably compensates for this deficiency and ensures an optimal nutrient base in every growth phase.

Calcium strengthens cell walls, improves plant stability and supports key metabolic processes. Magnesium is a key component of chlorophyll and essential for efficient photosynthesis. Together, both nutrients promote healthy development, better nutrient uptake and resilient plants.

Hesi CalMag is suitable for soil, hydroponics, coco substrates and irrigation systems and is particularly popular in modern LED grow setups, as plants under LED light often have an increased need for calcium and magnesium.

Benefits of Hesi CalMag

• Supplies plants with calcium & magnesium
• Ideal for soft water, osmosis water & demineralised water
• Supports strong cell walls and a stable plant structure
• Promotes lush green leaves and healthy photosynthesis
• Improves nutrient uptake
• Can prevent rot and deficiency symptoms
• Suitable for soil, hydro & coco
• Perfect for LED grow systems
• For all growth stages: from cuttings to flowering

Application & Dosage

Recommended dosage for soft water:

• Add CalMag to the irrigation water until an EC value of 0.4–0.5 mS/cm is reached.
• For osmosis water or distilled water (EC 0): 3–4 ml per 5 litres of water
• For soft tap water, reduce the dosage accordingly depending on the initial EC.

Increasing calcium and magnesium levels:

• Increase to 10 ml per 50 litres of water:
  • MgO by +15 mg/L
  • CaO by +10 mg/L
• Increase to 50 ml per 100 litres of water:
  • MgO by +38 mg/L
  • CaO by +25 mg/L

Nutrient content

NPK: 5-0-0

• 7.5% magnesium oxide (MgO)
• 5.0% calcium oxide (CaO)
• Also contains: iron chelate & molybdenum