| In order to study the water quality in fish tanks, a 166-day (January to July 1992) experiment was realized using the indigenous species "pacu" (Piaractus mesopotamicus). Two different protein levels were tested in the diet (16% and 34% crude protein) and three stocking densities (0.25, 0.50 and 0.77 fish/m²). From the results, it was observed that the interactions between stocking density and experiment length affected the characteristics bicarbonate and alkalinity, as well as the interaction between stocking density and protein levels affected concentrations of free and total CO2, conductivity and pH (P < 0.05). The water temperature in tanks changed significantly during the period of study (P < 0.05),decreasing gradually from summer to winter.... |
