During the 8-week experimental period, water temperature,
dissolved oxygen (DO) and pH were determined daily at 08:00 using a
multiparameter water quality instrument (YSI plus). Water samples
(100 mL) were collected weekly and filtered through pre-dried and
pre-weighed GF/C filter paper under vacuum pressure. Total ammonia
nitrogen (TAN), nitrite (NO2
−-N) and nitrate (NO3
−-N) concentrations
in the filtrate were measured according to standard methods
(APHA, 1998). Filter paper was used for total suspended solid (TSS)
determination.