The effect of Chinese pond mussel (Anodonta woodiana) as a biofilter on biochemical oxygen demand level in catfish (Clarias sp.) farming waste

Catfish farming, especially intensive farming will produce waste in the form of feces and leftover feed containing organic matter. Fish feeds are the highest (80%) contributor to organic matter in the farming environment. The amount of fish feeds not consumed or wasted in the bottom waters is about 20-50%. Waste from fish feeds and feces will accumulate and degrade the water quality. Chinese pond mussel (Anodonta woodiana) is a filter feeder capable of removing materials such as sediments and organic matter from the water column. The purpose of this research is to identify the effect of Chinese pond mussel (Anodonta woodiana) on the COD level in catfish farming waste. This study used a completely randomized factorial design with three treatment factors. The treatment factors were treatment factor of size (S) i.e. S0=control, S1=6-7 cm, S2=10-11 cm, treatment factor of density (D) i.e. D0=control, D1=5 mussels, D2=10 mussels, and D3=15 mussels, and treatment factor of time (at the 9th, 18th, and 36th hour). This experiment used three replications in a 10-liter container. Water quality parameters analyzed were temperature, pH, and COD. The result of this research showed that the best effect of Chinese pond mussel on the COD level was found in the treatment factor of density of 10 mussels with the size of 6-7 cm at the 9th hour. Factors having a significant effect on the COD level were size and density. The interaction between time and density factors and between size and density factors had a significant effect on COD level. The interaction between time, size, and density factors had a significant effect on COD level