Water quality parameters were within desired ranges for oyster culture (Table1). Observed
mean concentrations of ammonia, nitrite, and nitrate were all less than 1% of the lethal concentrations reported in Epifanio and Srna (1975) . Calcium supplementation was
required to the culture water because oysters demand a high level for growth. Approximately 95%
of the shell is calcium carbonate by weight (Yu et al., 2010 ). To the author’s knowledge,
no other study has implemented calcium supplementation for oysters in a closed system