An EC meter measures the electrical conductivity of the water. Clean water has a low EC. When you add nutrients and pH adjusters, the EC will go up. You can use this for measuring how many nutrients can put in the water without causing overfertilization. It can be hard sometimes to eyeball the required amount of nutrients. Sometimes, you're not quite sure how big your container water is or you have no means of measuring the nutrients accurately. Even if all these things are no problem, it is still possible that the recommended dosage of nutrients as printed on the label is too low for your plants, and your plants would benefit from a higher dose. Using an EC meter together with an pH meter, you can measure the optimum dose for your plants without causing overfertilization.
Glossary for Water Quality Testing Terms
Below are the terms relating to Water Quality Testing for the section you have selected.