Tilapia culture in trinidad and tobago: yet another update


Figure 6. Daily feed input during Trial 2



Download 1.98 Mb.
Page54/89
Date25.02.2021
Size1.98 Mb.
1   ...   50   51   52   53   54   55   56   57   ...   89
Figure 6. Daily feed input during Trial 2.



Figure 7. Daily feed input during Trial 3.

Figure 8. Daily feed input during Trial 4.

Most water quality parameters were in acceptable ranges for tilapia culture (Table 2). The TAN concentration spiked once to 8.55 mg/L in Trial 2 and once to 8.75 in Trial 4 for a short period (Figure 9). There was no observed mortality during these periods. Nitrite-nitrogen concentrations spiked once in each of Trials 1, 2 and 4. There was a peak concentration of NO2-N in Trial 1 of 13.62 mg/L, but this value was not included in the average (Table 2) because it was caused by mistakenly adding chlorinated water to replace evaporative losses. The chlorine appeared to affect Nitrobacter bacteria but not Nitrosomonas, as TAN levels did not increase during this period. In Trial 2 the peak NO2-N concentration of 18.27 followed the peak TAN concentration. In Trial 4 the peak NO2-N concentration of 13.58 mg/L coincided with the peak TAN concentration (Figures 9 and 10).




Share with your friends:
1   ...   50   51   52   53   54   55   56   57   ...   89




The database is protected by copyright ©essaydocs.org 2020
send message

    Main page