Low Cost Calibration Free pH Sensors for Water Quality Monitoring in the Aquaculture and Hydroponic Industries

The overall objective of this project is to develop and produce and demonstrate a prototype pH sensor, utilising a novel self-calibration system, for the aquaculture and hydroponic industry.

The need for sustainable food sources is evident, rising populations, increasing emissions of green house gases mean alternatives to the traditional farming and agricultural productions need to be found. This need is the key reason why there has been a significant growth in the aquaculture ($43 billion by 2023) and hydroponic industries ($16 billion by 2025). These industries allows crop production in intensive yields with little environmental impacts compared to the conventional farming techniques. To produce high yields efficiently and sustainably the quality of the water and the levels of nutrients within the water need to be routinely monitored. pH is the key chemicals parameters in understanding water chemistry. Very high (\>9.5) or very low (< 4.5) pH values are unsuitable for most aquatic organisms. The ideal pH of the nutrient solution for hydroponic crops is usually around 5.5-6.0\.

ANB Sensors Ltd (ANB), a UK micro-SME, have identified and filed patents for a disruptive enabling technology which allows the measurement of pH in demanding (low-salt and low-buffer capacity) aqueous media, such as drinking and seawater. The technology provides accurate measurements (+/- 0.01 pH units), without the need to re-calibrate the sensor, differentiating it from the state-of-the-art. The calibration free operation of ANB' pH sensor its small size mean that the sensor can be used within the aquaculture and hydroponics industry.