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.
It is important to note that your EC measurement only displays the complete amount of nutrients available to your plants. It will not show you the breakdown of each available nutrient or nutrient imbalances. You could have the perfect EC measurement, however there may still be nutrient deficiencies.
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.
The chart below provides a guide on preferred EC ranges for some of the most common crop types.
As mentioned above, in order for plants to thrive, it’s required they fall within the preferred EC ranges. If your crops sit outside these measurements for a period of time, they will start to demonstrate symptoms of poor plant health.
It can be difficult to diagnose problems with plants as they could be suffering with incorrect nutrient levels, affected by pests or it is the pH levels being too high or low that is preventing the uptake of nutrients. So even if the EC levels are within range as presented in the preferred EC range chart, it’s crucial to consider it could be some other factor that’s causing the plants to show symptoms of poor health.
Discover the most common nutrient deficiencies in plants and how to fix them to ensure you identify and isolate the problem. It is possible there are various deficiencies and toxicities that could be occurring at the same time.
Incorrect EC can be caused by the levels being either too low or too high. If your EC in plants is low, your crops will not be able to receive enough nutrients.
Symptoms when your EC is too low:
If your EC is too high, this can cause salt burn and nutrient toxicity.
Symptoms when your EC is too high:
Measuring your EC is vital as you get a closer look at what is occurring within your nutrient feed.
Prevention versus treating is the ideal course of action, and it is likely your EC will fluctuate over time, which is why it’s important to test your EC regularly. No matter what medium you are growing in, staying on top of measuring your EC will ensure issues can be identified and resolved early.
In hydroponics, you can add more (pH-balanced) water to your reservoir. This will dilute the concentration of salts and lower your EC.
In soil, the same applies where you will need to dilute the concentration of salts by adding pH-balanced water in growing pots or containers until fully saturated and drained.
Creating the optimum EC measurement isn’t only about adding or subtracting nutrients or water. It is recommended to change your nutrient solution regularly, to avoid putting your plants at risk of toxic nutrient levels. Measure EC daily, top up nutrients when necessary, and give your nutrients a refresh by emptying your tank when needed.
The best way to measure the conductivity (EC) of your plants is with a handheld conductivity pen. This is a robust handheld solution for measuring conductivity and temperature on the go. The Bluelab Truncheon is another favourite for growers.
To take care of the fundamentals, the Bluelab Combo Meter is the ideal device to measure the essential parameters of pH, conductivity and temperature. These fundamentals all play an important role in driving optimal plant health. Learn more about measuring and adjusting your fundamental parameters, as well the four plant health checks you should be doing every day to ensure you’re preventing health issues for your plants.
To learn more about plant growing and how to ensure optimal health for your crops, here are some helpful articles which will help you with all of your growing questions.
Featured products:
Bluelab Conductivity Pen
Bluelab Truncheon Nutrient Meter
Bluelab Combo Meter