Eficiência de Lithothamnium spp. na manutenção da qualidade de água em sistemas aquícolas com interface água-sedimento

Water quality is a key factor for the success of aquaculture systems, with pH, alkalinity, and hardness being essential parameters for environmental stability. This study aimed to evaluate the effect of Lithothamnium spp. on the maintenance of these parameters in microcosms with a water–sediment interface, comparing its efficiency with hydrated lime and dolomitic limestone. The experiment was conducted over 56 days using experimental units containing soil and water, arranged in a completely randomized design with four treatments (control, hydrated lime, dolomitic limestone, and Lithothamnium spp.) and three replicates. The products were applied directly to the water and reapplied whenever alkalinity dropped below 50 mg L⁻¹. Water quality parameters, including pH, alkalinity, and hardness, were monitored weekly, and soil chemical parameters were evaluated at the end of the experiment. The results showed that all liming materials improved water quality; however, Lithothamnium spp. and hydrated lime resulted in higher alkalinity and hardness compared to dolomitic limestone. Lithothamnium spp. showed similar performance to hydrated lime, with the advantage of promoting a more moderate increase in pH, indicating greater chemical stability. In the soil, treatments with liming materials increased pH, enhanced cation concentrations, and reduced potential acidity. These findings indicate that Lithothamnium spp. is an efficient and promising alternative for water quality management in aquaculture systems, combining effectiveness with improved operational safety.