// Definition
Electrical conductivity (EC) measurement taken directly at the root zone rather than from runoff water, providing more accurate nutrient concentration data especially in rockwool substrates. Higher EC correlates with greater osmotic pressure affecting water uptake and ultimately cannabinoid and terpene production.
// From the Episode
Isam from Canera recommended monitoring EC at the root zone rather than runoff specifically for rockwool grows, noting a significant gap between the two readings. He advised targeting 10-20% runoff during vegetative watering and no more than 15% during generative phase. He also cautioned against making drastic nutrient changes based on leaf analysis alone, as reference standards are too general and not genetic-specific. Dr. Mark Scialdone confirmed EC measures overall ionic content rather than specific nutrients.