EC value

The EC value (from "electrical conductivity") measures how many dissolved nutrient salts are in a solution. The more nutrients in the water, the better it conducts electricity – and the higher the EC value. This makes the EC value the counterpart to the pH value: The pH indicates whether nutrients can be absorbed, while the EC indicates how much is available.

What the EC value measures

Pure water conducts hardly any electricity. As soon as fertilizer is added, the conductivity increases. The EC value (usually given in mS/cm) is therefore a measure of the "strength" of the nutrient solution. It is measured with an EC meter. The value helps to dose the fertilization: A low EC means weak fertilization, a high EC means strong fertilization. However, too much of a good thing quickly leads to over-fertilization.

Reference values depending on the phase

The appropriate EC value depends on the stage of development. Young plants and seedlings can only tolerate a little, so they need a low EC. In the vegetative phase and the flowering phase, the demand increases, and the EC can be higher. Specific target values differ depending on the fertilizer, strain, and substrate – the principle is: it's better to cautiously approach it than to overdo it.

Frequently asked questions about the EC value

What does a high EC value mean?

Many dissolved nutrient salts, i.e. strong fertilization. If it is too high, there is a risk of over-fertilization with burned leaf tips.

How do I measure the EC value?

With an EC or conductivity meter. Some combination devices measure pH and EC values together.

Do I even need to pay attention to the EC value?

In soil, you can often do without it. In hydro and on coco, however, checking the EC value is very useful.