The advancement of aquaculture practices relies on the accurate and reliable measurement of water quality parameters, which are critical for optimizing growth conditions for aquatic species. This study presents a comparative analysis of two portable spectrophotometers—the HACH® DR 1900 and the Lamotte Spin Touch®—commonly used in aquaculture extension services. The analysis focuses on their performance in quantifying key water quality indicators, including total ammonia nitrogen (TAN), dissolved oxygen (DO), pH, and salinity.
To assess repeatability, multiple analysts performed identical tests on the same water samples using each device. Variability in results between analysts and repeated measurements was analyzed to identify any user-dependent variation or equipment precision issues. Additionally, the accuracy of both devices was evaluated using the spike-recovery method (Boyd and Tucker, 1992), where water samples with known TAN concentrations were spiked with 0.30 mg/L TAN and re-analyzed. The percentage recovery of the spike provided a quantitative measure of each device’s accuracy, with recovery rates closer to 100% indicating higher accuracy.
Statistical methods, including standard deviation, coefficient of variation, and analysis of variance (ANOVA), were used to assess repeatability, variation, and differences in accuracy and time efficiency between the two devices. Lower variability and higher recovery percentages suggest greater repeatability and accuracy, respectively, while ANOVA results indicate if significant differences exist between device performances and among analyst results, thus evaluating user-dependent variability.
This study provides aquaculture practitioners with insights into the cost-effectiveness, time efficiency, accuracy, and repeatability of the DR1900 and Lamotte Spin Touch. By understanding the economic and practical aspects of water quality testing equipment and the influence of analyst variation, environmental managers and researchers can make informed decisions when selecting equipment for long-term water quality monitoring, ultimately contributing to improved standardization and reliability in aquaculture practices.