pH & CF / EC Meters & Controllers

EC and CF are measures of electrically charged nutrient ions, in hydroponics this is the best way to measure a reservoirs mixed nutrient solutions strength. Tap or Tank water usually conducts electricity because it is full of impurities, where absolute pure water will not conduct electricity, in a hydroponic reservoir it has plenty of electrically charged nutrient ions. When EC conductivity probes called electrodes are placed in a nutrient solution, an electrical current passes from one electrode, through the water to the other electrode and the meter counts the number of electrically charged ions present. The reading is then presented as an Electrical Conductivity (EC) reading or Conductivity Factor (CF) reading. CF is a scaled up version of EC, basically CF is EC multiplied by 10.

Potential Hydrogen, commonly known as pH, is a number that indicates the acidity (Below 7.0pH) or alkalinity (Above 7.0pH) of a solution i.e. water or nutrient rich water. It is important to maintain a hydroponic nutrient solution at a pH where elements in the nutrient solution are most available to the plant. Each nutrient element has a pH range in which its availability to the plants is maximised. In hydroponics, the range in which most elements are available is typically between 5.5pH and 6.5pH. Strong acid (Low pH) or strong alkali (High pH) conditions can upset the balance of a nutrient solution. This can cause a loss of uptake for specific nutrients by the plants roots. This is known as "lockout", whereby certain elements become unavailable to the plant to absorb due to high or low pH.