EC (electrical conductivity) is an essential measurement of the total amount of food or nutrients available to your plants. EC is really important, as it communicates with you if your plants are receiving the correct amount of food.
Therefore, if your plant has an incorrect EC level, it may start to show signs of stress. Too high, and the plant will show signs of toxicity, too low and the plant will have a nutrient deficiency.
It's helpful to know that plants can only absorb nutrients when they’re in ionic form. When nutrients dissolve in water, they split into ions which carry an electrical charge and the potential for electricity to move through the solution. If we look at pure water—RO, or reverse osmosis water—as an example, it would be a poor conductor of electricity, as it doesn’t contain any ions. The more ions there are, the more electricity it conducts.
So, the more nutrients that are in the water, the higher the EC. This is good news because that gives us a level of control. We can visually check the plants for signs of stress (incorrect EC), measure the EC level using a meter, then correct it by adding more nutrients.
A common mistake made with growers can be to feed your plants as much as possible to ensure there is plenty of nutrients available. This can however have major repercussions. Plants have a preferred conductivity range in order to achieve optimal health.
For more information, read the article at www.blog.bluelab.com.