A measure of dissolved mineral salts in a nutrient solution, expressed in mS/cm. Used to gauge overall nutrient concentration.
Electrical Conductivity (EC) measures the ability of a nutrient solution to conduct an electrical current, which increases as more mineral salts are dissolved in the water. It is expressed in milliSiemens per centimetre (mS/cm) and is the standard metric for managing nutrient concentration in hydroponics and growing media.
Pure water has an EC of approximately 0 mS/cm. As nutrients are added, the EC rises. Most tap water has an EC of 0.2-0.6 mS/cm, which must be accounted for when mixing nutrients.
Typical target EC ranges:
EC does not measure which nutrients are present - only the total ionic strength. A high EC indicates high nutrient concentration, but does not distinguish between balanced and imbalanced nutrition. Regular monitoring of EC alongside pH provides the foundation of nutrient management in any growing system.
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