Statistical Analyses
Treatment effects were evaluated by two sample t-tests using Statistix
version 4.1 (Analytical Software, Tallahassee, Florida) to compare water
quality and harvest data. Growth performance and feed conversion
were measured in terms of final individual weight (g), percentage survival,
total yield (kg/ha), and FCR. Production/size index (PSI), was
calculated as PSI = production (kg/ha) average weight (g) 1,000
(Tidwell et al. 2000). Percentage and ratio data were converted to arc
sine values prior to analysis. These data are presented untransformed to
facilitate comparison and interpretation. Level of significance was determined
at P = 0.05.