In this study, F-values of 24.17 for PNSBsi model and 197.89 for ORP model, signify that the models were significant ( Table 2). ANOVA at the low probability value (P > F) also demonstrated that the quadratic model of PNSBsi value (P > F = 0.0002) and ORP value (P > F < 0.0001) were significant. However, a lack of fit F-values of 6.5775 and 2.64 of these models suggested that it was not significantly relative to the pure error.