The recirculation system used for seven years at BPBL Ambon continues to be developed using simple and affordable technology so that it is easy to apply by cultivators. In order for the recirculation system to be able to provide more optimal results in clownfish rearing, it is necessary to carry out research on the differences in biological filters in recirculation systems so that the components of a good filter media used in cultivation activities can be identified.
In this experiment there were three different filter media treatments, namely Treatment A (Ginger Coral), Treatment B (Kaldness K1) and Treatment C (Bioblock). In this experiment, seeds were spread with a size of 2 cm as many as 900 individuals per recirculation system unit. The feed given is commercial pellet feed, amounting to 5 - 10% of the total biomass. The frequency of feeding is 3-4 times a day and given in the morning, afternoon and evening.
The water quality values in the three treatments tend to be the same and are still within normal limits where the temperature is in the range of 26.1 – 28.2 oC , salinity 32 – 33 ppt, DO 4.31 – 5.91 mg/l, Nitrite 0.038 – 0.576 mg/l, Ammonia 0.002 – 0.130 mg/l, Nitrate 0.01 – 1,080 mg/l. In treatments A and B the pH value was at optimum conditions, however in treatment C the pH value was quite low, namely 6.36. As a result, there was quite high mortality in treatment C. The highest survival value was in treatment A, namely 87.11%, followed by treatment B at 86.67% and treatment C at 53.33%. The value of increase in length during the two month maintenance period tended to be the same as in treatment A namely 1.25 cm, followed by treatment B at 1.3 cm and treatment C at 1.26 cm.