How to Monitor Nutrient Solution in Hydroponics

What is Hydroponics?

Hydroponics is the art of growing plants without soil. There are several different categories of hydroponics systems:
• Wick
• Water Culture
• Ebb and Flow (Flood & Drain)
• Drip (recovery or non-recovery)
• N.F.T. (Nutrient Film Technique)
• Aeroponic

Hydroponic Nutrients:

The commonality of all the systems listed above is that they are heavily dependent on nutrient solution in order to ensure proper plant growth. The plants in all the above systems grow in media that provides no nutritional value, so having proper nutrient solution is vital to plant life. It is crucial that the nutrient solution is monitored and fed properly to the plants.

Monitoring Nutrient Solution:

The two most important parameters of your nutrient solution to monitor and control are the pH and EC (electrical conductivity).

pH of Hydroponic Nutrient Solution:

The pH of the nutrient solution indicates whether it is alkaline, acidic or neutral. If a the pH is greater than 7, it is alkaline; if the pH is less than 7, it is acidic. A pH of 7 indicates that the solution is neutral. The plants ability in a hydroponic garden to absorb nutrient solution depends on the pH of the nutrient solution. When the nutrient solution is above or below the optimal pH level, the plant may not receive enough nutrients. Different nutrients are available at different pH ranges. In hydroponics, the ideal pH range is between 5.8 and 6.2, compared to a pH of 6.5 for soil gardens.

EC of Hydroponic Nutrient Solution:

Hydroponics gardens may contain different varieties of plants, and different plants require different nutrient solution concentrations for growth. It is important to control nutrient solution concentrations in order to provide the optimal conditions in the root zone. This allows the maximum uptake of nutrients into the rest of the plant’s cellular structure. Nutrient solution concentration can be monitored and controlled using electrical conductivity measurements. Electrical conductivity is measure of the ionic strength of a solution and can be converted into concentration.

Conclusion:

Hydroponics is an extremely useful technique used for growing, but is heavily dependent on monitoring the pH and EC of the nutrient solution being used.  With the proper measurement and control of pH and EC, growers will be able to get the most out of their hydroponic systems and grow large, healthy plants.

Looking to design a hydroponics monitoring system?

Check out our application note for a more detailed explanation of hydroponics water treatment systems, including a system diagram and product selection tips: