Table 3. Water quality parameters in the rearing tanks of Pacific white shrimp (Penaeus vannamei) post-larvae fed different levels of poly-β-hydroxybutyrate (PHB) incorporated experimental diets for five weeks

	Ammonia¹⁾	Nitrite²⁾
P0.0	0.038 ± 0.002	0.98 ± 0.10^ab
P.25	0.038 ± 0.003	1.03 ± 0.07^a
P.50	0.038 ± 0.001	0.95 ± 0.05^ab
P1.0	0.035 ± 0.003	0.97 ± 0.10^ab
P2.0	0.032 ± 0.004	0.85 ± 0.10^b
Pr > F^*
ANOVA	0.098	0.042
Linear	0.018	0.086
Quadratic	0.146	0.220
Regression
Model	L	NS
Adj R²	0.318	0.152

P0.0, P.25, P.50, P1.0 and P2.0 are 0.00%, 0.25%, 0.50%, 1.00% and 2.00% PHB incorporated diet treatments.
If statistical significance (p < 0.05) was detected, the model that best fit the data was chosen.
Values are the mean of triplicate (n = 3) and presented as mean ± SD.
Ammonia NH₃ (mg/L).
Nitrite NO₂-N (mg/L).
Values with different superscript letters in the same column are significantly different (p < 0.05).
Significance probability associated with the F-statistic.
L, linear model; Q, quadratic model; NS, no structure; Adj R², adjusted R².