pH and EC measurement and control for water

Hydroponic nutrient water for the plants has to be with right quality for optimal plant growth. Plant growth is influenced by the water temperature, the amount of oxygen, the amount of nutrients and the pH of the water. This product group deals with the measurement and adjustment of water pH and EC values.

If you focus on growing green plants and house plants on green wall the measuring and adjusting water quality is usually not the most critical parts for plant growing. However, if you grow food crops and want to optimize their quality growth, you should take some time to measure and treat nutrient water.

pH meter and water pH value measurement

The acidity or alkalinity of nutrient water is illustrated by a pH value ranging from one to fourteen. Value 1 means very acidic when the value 14 is again very alkaline. The optimal pH of plant nutrient water varies slightly with different plants, but the good pH value for hydroponics is usually 5.2-6.2.

The pH of the nutrient water can be adjusted with pH+ and pH- cemicals.

Water pH measurement is most easily done with a digital meter. The digital pH meter needs to be calibrated regularly, about once a month. The pH meter is calibrated using a pH calibration solution or a pH calibration fluid. Dip the meter head into the calibration solution and adjust the meter to the pH indicated by the calibration fluid, which is usually 7.0 or 4.0.

EC meter and nutrient value measurement

The amount of nutrients dissolved in nutrient water is represented by the EC value of water. EC stands for Electrical Conductivity and describes the electrical conductivity of the liquid. The more nutrients and impurities in the water dissolved in the ionic form, the higher the EC value.

In practice, therefore, the EC value changes according to the amount of fertilizers added and used by plants growing in the nutrient mixture.

To reduce the EC value, clean water is added to the water tank. To increase the EC value, nutrients are added to the water tank. If the EC value of water rises during time, it is a sign that plants are unable to use nutrients in water. This may be due to the wrong nutrients or wrong pH value of the water.

The EC value is easiest to measure with a digital EC meter. The digital EC meter needs calibrating regularly, about once every two months. Calibration of the EC meter is performed using EC calibration solution or calibration fluid, also called EC calibration buffer. Dip the meter head into the calibration solution and adjust the meter to the number indicated by the calibration fluid, which is usually 2.8.