Resource icon

Growing Cannabis: What is the Difference Between PPM and EC?

Cannabis cultivation is both an art and a science. To achieve the best results, growers must carefully balance various environmental factors, including lighting, humidity, and the concentration of nutrients in the growing medium. Two critical measurements for nutrient concentration are Parts Per Million (PPM) and Electrical Conductivity (EC). This article will explore the differences between these two metrics and explain their significance in cannabis cultivation.

Introduction to PPM and EC​

Before discussing the differences between PPM and EC, it's essential to understand what each term means and why it's relevant to cannabis cultivation.

What is PPM?​

PPM stands for Parts Per Million, a unit of measurement that indicates the concentration of a substance in a solution. In the context of cannabis cultivation, PPM refers to the number of nutrient ions present in the water or nutrient solution used to feed the plants. A higher PPM value signifies that there are more nutrients in the solution, while a lower value indicates a lower nutrient concentration.

What is EC?​

EC, or Electrical Conductivity, measures the ability of a solution to conduct electricity. Since nutrient ions are charged particles, their presence in a solution affects the solution's ability to conduct an electrical current. As a result, EC is an indirect way of measuring the concentration of nutrients in a solution. Higher EC values correspond to higher nutrient concentrations, and lower EC values indicate lower concentrations.

The Relationship Between PPM and EC​

While PPM and EC are different units of measurement, they are closely related when it comes to measuring nutrient concentrations in cannabis cultivation. The relationship between PPM and EC can be summarized as follows:

  • PPM measures the concentration of nutrient ions in a solution.
  • EC measures the ability of a solution to conduct electricity, which is affected by the presence of nutrient ions.
  • Higher PPM and EC values indicate higher nutrient concentrations, while lower values signify lower concentrations.
In general, EC is considered a more accurate and reliable metric for measuring nutrient concentration, as it is less influenced by factors such as temperature and ion type. However, both PPM and EC can be used by cannabis growers to ensure that their plants receive the appropriate amount of nutrients.

Understanding PPM and EC Values in Cannabis Cultivation​

To grow healthy cannabis plants, it is crucial to provide them with the right balance of nutrients. PPM and EC values can help growers determine whether their nutrient solution is too concentrated or too diluted. Here is a general guideline for PPM and EC values in cannabis cultivation:

  • Seedlings: 100-250 PPM (0.2-0.5 EC)
  • Early Vegetative Growth: 300-400 PPM (0.6-0.8 EC)
  • Late Vegetative Growth: 450-700 PPM (0.9-1.4 EC)
  • Flowering Phase: 750-950 PPM (1.5-1.9 EC)
These values are approximate and may vary depending on the strain of cannabis being grown and the specific nutrients used. It's essential for growers to monitor and adjust their nutrient solution's PPM and EC values as needed to ensure optimal plant health and yield.

How to Measure PPM and EC​

To measure the PPM and EC of a nutrient solution, growers can use specialized meters designed for this purpose. These meters are widely available and relatively affordable, making them an essential tool for cannabis cultivation.

When using a PPM or EC meter, it's essential to calibrate it regularly to ensure accurate readings. Calibration typically involves using a standard solution with a known concentration and adjusting the meter until it displays the correct value.


In summary, PPM and EC are essential measurements for cannabis growers to monitor and adjust nutrient concentrations to ensure optimal plant health and yield. While EC is considered a more accurate and reliable metric, both PPM and EC can be used effectively in cannabis cultivation. By understanding the differences between these two measurements and how to use them, cannabis growers can provide their plants with the ideal balance of nutrients and achieve the best possible results.
First release
Last update
3.00 star(s) 1 ratings

More resources from logic

Top Bottom