Electrical conductivity (EC)
A measure of a solution's ability to carry electric current, used as a fast indicator of total dissolved ion concentration but not of any specific nutrient.
Electrical conductivity measures how readily a solution carries electric current. In cultivation, it is used as a practical proxy for total dissolved ion concentration. It does not identify individual nutrients, so two solutions can have the same EC while carrying different amounts of calcium, nitrate, potassium, or other ions.
Feed EC describes concentration, not the total nutrient dose delivered to each plant. If feed EC stays unchanged while irrigation volume falls, the total amount of nutrients delivered also falls. This distinction is especially important when evaluating calcium delivery.
Interpret EC as a trend alongside pH, delivered irrigation volume, substrate water content, and drain volume. A rising root-zone or drain EC can reflect concentration during dryback Dryback The decrease in a growing substrate's water content between irrigation events, commonly tracked as a change in volumetric water content. , limited leaching, uneven irrigation, or changes in plant uptake. EC is a useful signal, but one reading cannot identify the cause by itself.