atefeh ferdosian

The aim of this study was to investigate the effect of using basalt in reducing the nitrogen content of water and the growth performance of goldfish (Carassius auratus) for 60 days.

For this purpose, 245 pieces of goldfish with a mean weight of 9.42 ± 0.15 g and a longitudinal mean of 3 ±0.02 cm were purchased and after adaptation for one week in distribution experimental treatments. Were. Experimental treatments included control treatment (without filter), zeolite with 10 g/l, basalt with different amounts of 10, 20 and 30 g/l and for each level of filter, fish density during the experiment, two densities of 1.5 And 3 cm per liter were considered, which were randomly distributed to 25 pieces of fish for a density of 1.5 and 50 pieces for a density of 3 in 50 liter aquariums.

The results of this study showed that the presence of filtration had a positive effect on fish growth rate and fish had better growth factors in treatments of both densities that had filters compared to the control group (p<0.05). Ammonia, nitrite and nitrate levels in the eighth week of the study in treatments containing filters of both densities were significantly lower than the control treatment and did not exceed the toxic range (p<0.05).

According to the studies, it was found that basalt volcanic rock has a very high ability to absorb nitrogen compounds in water and 10 g/l basalt can be treated as a substitute for 10 g/l zeolite with a long reduction time more suggested.