Combined effect of filtration method (carbon, zeolite and simple filtration) and stock density of Macro (Labidochromis caeruleus) on growth and nitrogenous compounds of water

Water physicochemical factors have an important role in the health of fish. In this study, the effect of filtration and density of Macro fish on water nitrogenous compounds was studied. For this purpose, the concentrations of water biochemical parameters (ammonia, nitrite, nitrate and pH) were measured at three densities and three filtration methods (carbon filteration, zeolite filteration, and control, simple filteration). Water samples collected in a period of one month and three days intervals and were immediately investigated. Data were compared using two-way ANOVA. The results showed that the average concentration of nitrate in the three types of filter in three densities had no significant difference. The average concentration of nitrate in comparison with filtration, between filtration of the zeolite group and control group was significantly different. Also, between filtration of the carbon group and control group was significantly different. In this regard, there was no significant difference between filtration of the carbon group and filtration of the zeolite group. The results showed that the average of pH level in the three types of filter in three densities had no significant difference. In comparison between the averages of pH level with filtration, between filtration of the zeolite group and control group and filtration of the carbon group and control group had significant difference. But there was no significant difference between filtration of the zeolite group and filtration of the carbon group. The counter effect of filtration and density, a significant relationship was not found and no difference in the average of other factors was observed in other groups.