What is EC Hydroponics and how to measure and optimize it

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EC in hydroponics is one of the most important factors that determine whether your plants live and thrive, or wither and wilt. So before we go into how to measure and optimize EC Hydroponics, let’s first talk about the meaning of this term.

What Does EC Stand For In Hydroponics?

EC stands for Electrical Conductivity. It is a measure of the total concentration of all the positively charged ions in a solution.

EC is measured in units of MilliSiemens. The alternative measurement is PPM (Parts Per Million) where the actual value can vary depending on which country you’re in and what equipment is used to measure it.

That is why measuring EC and using EC meters is easier for most hydroponic gardeners and growers, since it is a standard unit and you can then get information from anywhere that deals with conductivity without having to translate and convert the units.

What Is EC Hydroponics Measurement?

In hydroponics, we measure EC to determine how strong our nutrient solutions are. In simple terms: The higher the EC value, the more concentrated your solution is.

Since the nutrients are salts and minerals in nature (very specific ones. Don’t try to add salt to your plants – that will kill them), adding more nutrients to the water, increases the conductivity, whereas adding more water, decreases it.

Different plants require different EC levels in hydroponics because of the level of sensitivity they have for salts. If you get just the right concentration of nutrient solution, your plants will grow faster and produce bigger and healthier crops for you.

What Should The EC Be For Hydroponics?

The ideal EC range for most plants is between 1.8 and 2.2. This varies depending on what you are growing, how old your plants are, etc.

Luckily for us, there are general usage nutrient solutions, with specific instructions on each product which tell you how much nutrient to put in the water.

There are also powder nutrients for more advanced and for commercial growers, which are specifically adjusted for certain crops, so you’ll have strawberry nutrients for strawberries, and tomato nutrients for tomatoes. The only thing for you to do is to measure the EC daily.

If it rises from one day to the next, it means that the plants are taking in more water than nutrients, and you need to add water, while on the other hand if the EC decreases, it means your plants are “eating” more nutrients than water and you need to add more nutrients to the solution.

It may take some trial and error to find the optimal EC + pH for your plants, but your plants will tell you if they need more or less nutrients by their symptoms (such as drooping leaves) and their health and thriving produce.


Here’s a short video to get a quick bearing on EC:

How To Measure EC In Hydroponics?

Since EC is literally electrical conductivity, you need an electrical measuring device to measure it. There are various types of EC meters and combined measuring devices, which vary in price, durability, and accuracy.

For home and garden uses, you can buy a pocket EC meter on Amazon like this one (click). It is a simple solution when you want a hand-held device.

For larger systems, it is better to use combined measurement devices such as this 5-in-1 Water Quality Multi-Parameter monitor (click to see the product on Amazon), which can stay in the water for longer times and requires less calibration. The added advantage is that it also measures the pH level and the temperature at the same time, and you can mount it on your reservoir for constant monitoring.

How To Use An EC Meter In Hydroponics?

Just like any other measuring device, it needs to be calibrated before use. You do that by putting the probe into distilled water and then, depending on your model, you press a button to calibrate (or set) it.

Now, wait until the EC meter completely dries and place the probe in the water. wait a minute or so for it to settle on a stable reading and you’re done.

That’s pretty much all there is to measuring the EC of your hydroponics system. If you want more control, better benefits from your plants then you should keep a journal with daily measurements. This has 2 purposes:

  1. To monitor the fluctuation of the EC (and pH and temperature) over time – to see if your plants are taking in more water or more nutrients out of the solution, and to keep the solution EC as steady as possible,
  2. To see how your plants and crops are reacting to the levels of EC combined with pH and temp, and to adjust the levels accordingly.


I hope you found this article beneficial and you know more now about EC and how to handle it in your own hydroponic system and with your own plants.

Shaun Anderson

Shaun Anderson

I love my garden, especially growing my own (and my family’s) food, so I decided to go into Hydroponics and learn all that I can on the subject.

Join me on this journey and discover how it all works.

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