Evaluation of ceramic as a filter material in the recirculating water system of fish aquaria

The efficiency of a ceramic filter material was compared with the sand and mixture of ceramic and sand, based on water quality parameters, phosphatase activity and bacterial population in the recirculating water system of carp rearing tanks. The concentration of COD and total ammonia in the water of ceramic filter tank, fluctuated at higher levels compared with the other filter tanks. Other parameters, including the bacterial density, changed variably at about the same levels in all filter tanks. The V max and Ks of ACPA in the water of ceramic filter tank was higher than that of other two tanks. In nitrification, the stability of ceramic filter system was not achieved, because the total ammonia level was quite high until the end of the experiment. In addition, the pH value of the ceramic filter tank decreased to 5.25 at the end of experiment. These results strongly suggest that an improvement of the ceramic as a filter material, is required.