EC for plants – Metrop. EC stands for Electric Conductivity (mS/liter) and with that we measure the amount of (usable and unusable) salts in water. Plants that grow and flower rapidly must have sufficient nutrients available. To measure the nutritional value (actually the nutritional salts) you use an EC meter.The EC meter simply measures the amount of electrical resistance in water and that also explains why a medium like soil must be wet if one measures it. An EC meter measures a total sum of all salts. An EC of 0.1/100L from one brand of nutrition therefore does not have to have the same nutritional value as an EC of 0.1/100L of the other brand.
Most cheaper plant foods contain many elements such as chloride, cadmium and other heavy metals. Cultivators who grow their crop by weight also try to get the plant to absorb as many nutrient salts as possible for a heavier end result. The best way to measure this in nft systems is by withdrawing some water from the medium with a syringe and then measuring it.