Results
During the study period, overall water quality values averaged (±SD): dissolved oxygen, 6.0 ± 0.4 mg/L; temperature, 22.2 ± 0.4 C; pH, 7.2 ±0.3; unionized ammonia–nitrogen, 0.014 ± 0.007 mg/L; total ammonia–nitrogen, 0.94 ± 0.13 mg/L; nitrite–nitrogen, 0.74 ± 0.28 mg/L; alkalinity, 93.6 ±14 mg/L; and total hardness, 156 ± 14.4 mg/L. Water quality parameters were within ranges suitable for health and growth of Mekong giant catfish (Pholprasith and Tavarutmaneegul, 1997).