The Effect of Leonardite on pH in Aquaculture and Its Stabilization with Clinoptilolite

Abstract

In aquaculture systems, pH values between 6.5 and 8.5 are generally considered suitable; however, the optimum range may vary depending on the cultured species, water alkalinity, temperature, and production system. In the present study, the effects of the natural adsorbents leonardite and zeolite on pH were investigated. Two different particle sizes of leonardite, namely powder and gravel forms, were used at three different concentrations (3, 6, and 9 mg/L), while zeolite was added in gravel form (3–5 mm) at three different concentrations (3, 6, and 9 mg/L). The experiment was conducted for a total of six days, during which pH values were recorded.

During the first three measurements, the effect of leonardite on water pH was determined. Following this stage, gravel-sized zeolite was added to the experimental groups, and its influence on pH values in terms of acidic or basic shifts was evaluated. At the end of the experiment, the differences among groups in terms of pH values were found to be statistically significant (p < 0.05). Final pH values ranged between 6.50 and 7.64, indicating that the recorded values remained within a suitable range for many freshwater species. In conclusion, the combined use of the natural adsorbents leonardite and clinoptilolite may be considered suitable for pH stabilization in freshwater aquaculture.