The experiment was conducted at the Aquaculture Research Facility of the Asian Institute of Technology, Thailand (13.06◦N latitude and 100.62◦E longitudeat an altitude of 2.7m). A 2×3 factorial design consisting of pond water filtration as the first factor, versus unfiltered pond water, and three different growth media as the second factor, i.e. the control treatment (2cm thick 1m2 styrofoam sheet), gravel (2.5cm in size) and builders’ grade sand (0.1–0.25mm in size), were used in this study. There were six treatments in triplicate: (A) unfiltered pond water and styrofoam sheet; (B) unfiltered pond water and gravel; (C) unfiltered pond water and sand; (D) filtered pond water and styrofoam sheet; (E) filtered pond water and gravel; (F) filtered pond water and sand.