Table 4. The environmental parameters in 5 rearing tanks of Litopenaeus vannamei during the experimental period

Parameters	Percentages of a mixture of FPH and HA (wt.%) in fishmeal
Parameters	Treatment 1 (control)	Treatment 2 (1 %)	Treatment 3 (3 %)	Treatment 4 (5 %)	Treatment 5 (7 %)
Temperature (°C)
AM	29.50 ± 0.08^a	29.50 ± 0.07^a	29.40 ± 0.08^a	29.70 ± 0.09^a	29.60 ± 0.07^a
PM	30.10 ± 0.09^a	30.50 ± 0.08^a	30.60 ± 0.08^a	30.60 ± 0.06^a	30.50 ± 0.05^a
pH
AM	7.55 ± 0.02^a	7.55 ± 0.03^a	7.55 ± 0.02^a	8.05 ± 0.01^b	8.00 ± 0.02^b
PM	7.75 ± 0.01^a	7.55 ± 0.02^a	7.95 ± 0.01^b	8.15 ± 0.02^b	8.05 ± 0.03^b
DO (mg/L)	5.50 ± 0.25^a	5.50 ± 0.20^a	5.50 ± 0.22 ^a	5.50 ± 0.24^a	5.50 ± 0.22^a
Alkalinity (mg CaCO3/L)	103.3 ± 0.85^a	105.2 ± 0.92^b	105.8 ± 1.17^b	105.5 ± 1.09^b	107.5 ± 1.22^b
Nitrite-N (mg/L)	0.55 ± 0.09^a	0.42 ± 0.04^a	0.32 ± 0.06^b	0.30 ± 0.07^b	0.32 ± 0.09^b
Total ammonia-N (mg/L)	0.23 ± 0.07^a	0.33 ± 0.05^a	0.27 ± 0.05^a	0.31 ± 0.04^a	0.29 ± 0.04^a

Different letters in the same row indicate statistical significance (p < 0.05, Tukey’s multiple comparisons).
FPH, fish protein hydrolysate; HA, nano-hydroxyapatite; DO, dissolved oxygen.