Pioneering Hydroponics

Since 1976

Guide to EC Levels in Hydroponics

EC and pH levels go hand-in-hand in hydroponics.

pH provides insight into the nutrient balance of your nutrient solution and EC levels provide an indication into the quantity of nutrients available in the solution.

However, EC levels in hydroponics don’t say what nutrients the solution has and at what levels. EC gives you an overall level of nutrient concentration - it measures the total dissolved salts/solids in the nutrient solution.

An EC meter gives you accurate level measures in mS, ppt, uS, and ppm.


How Does EC Affect Plant Growth?

When the EC level is too high, which translates to how strong the solution is, it will cause nutrient burn on delicate plants, seedlings, and delicate plants. The concentration of the nutrient solution can be increased for the vegetative stage according to the type of plant you’re growing.

For a grow room with a mixture with plants, you’ll need to separate them into heavy feeders, medium feeders, and light feeders if you have them. With every feed rate, you’ll need a separate reservoir.

As an example, feeding lettuce with EC levels suited for tomato plants’ needs will result in the former being bitter. On the other hand, feeding tomatoes with EC levels suited for lettuce needs results in the tomatoes having no taste.


Do Water and Air Affect EC Levels?

Nutrient solutions should have temperatures between 18℃-26℃, as plants don’t like when water temperatures change rapidly. This is particularly vital around plants’ root zone, so make sure that any water you add to the reservoir matches its temperature.

You also need to account for ambient temperatures; warmer climates may require chilling options for the nutrient solution and colder climates may require a heater.

Ventilation and airflow also affect. EC levels. With ventilation, you’re discarding old air and introducing new air, and with airflow you’re moving the same air. Better ventilation will result in higher transpiration rates, which leads to plants increasing their nutrient absorption and intake rates.


What Should You Do When EC Levels Change?

If EC levels increase and:

  • pH also increases, lower the EC by 0.2.

  • pH decreases, change the reservoir and lower the EC.

  • pH doesn’t change, lower the EC by 0.2.


If EC levels decrease and:

  • pH increases, raise EC by 0.1.

  • pH also decreases, change the reservoir and raise EC by 0.2.

  • pH doesn’t change, raise EC by 0.2.


If EC levels don’t change and:

  • pH increases, this is normal and you should continue growing as you are unless the level changes by more than 0.5. Should this occur, you need to change the reservoir and re-feed at a lower EC level.

  • pH decreases, change the reservoir and lower EC.

  • pH also doesn’t change, this is perfect!



What if the EC Levels Change But the Water Levels Don’t?

EC levels increase and:

  • pH also increases, raise the EC as plants are leeching certain foods.

  • pH decreases, change the reservoir and increase EC.

  • pH doesn’t change, raise EC by 0.2 as plants are leeching certain foods.


EC levels decrease and:

  • pH increases, change the reservoir and lower EC.

  • pH also decreases, lower EC or change the reservoir.

  • pH doesn’t change, lower EC by 0.2 as plants are eating but not drinking.


EC levels don’t change and:

  • pH increases, lower EC by 0.2.

  • pH decreases, change reservoir and readjust levels.

  • pH also doesn’t change, lower EC by 0.2.

Controlling EC levels in hydroponics is essential for strong and healthy plants. Make sure to get in touch with us on 01695 554 080 or 01226 320 850 if you want to know more about our hydroponics products.

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