Table 5. Change of water quality (DO, pH, temperature, EC, turbidity, TAN, NO2-N, NO3-N and PO4-P) in HP for 12 weeks

Week DO (mg/L) pH Temperature (°C) EC (μs/cm) Turbidity (NTU) TAN (mg/L) NO2-N (mg/L) NO3-N (mg/L) PO4-P (mg/L)
1 Not measured
2 9.11 ± 0.17 5.89 ± 0.44 21.1 ± 1.0 821.4 ± 32.6 0.98 ± 0.21 4.65 ± 0.74 0.016 ± 0.006 47.93 ± 0.68 15.95 ± 0.07
3 9.04 ± 0.21 5.60 ± 0.70 22.4 ± 1.5 746.8 ± 16.2 1.16 ± 0.14 4.00 ± 0.68 0.019 ± 0.008 47.52 ± 0.71 14.89 ± 1.30
4 8.84 ± 0.19 5.42 ± 0.20 22.0 ± 0.7 674.5 ± 19.8 0.96 ± 0.08 0.54 ± 0.18 0.018 ± 0.011 43.63 ± 1.94 15.97 ± 1.08
5 8.90 ± 0.13 5.45 ± 0.39 23.7 ± 1.0 681.0 ± 57.9 0.50 ± 0.32 0.18 ± 0.17 0.006 ± 0.002 33.17 ± 2.66 14.99 ± 0.64
6 9.18 ± 0.26 5.42 ± 0.99 23.5 ± 1.2 966.3 ± 11.0 0.73 ± 0.25 1.00 ± 0.27 0.016 ± 0.021 47.97 ± 0.57 15.33 ± 0.22
7 9.20 ± 0.09 5.82 ± 0.01 23.1 ± 1.1 907.5 ± 7.8 1.50 ± 0.49 0.19 ± 0.25 0.022 ± 0.001 38.80 ± 0.14 14.78 ± 0.06
8 9.56 ± 0.07 6.06 ± 0.07 22.7 ± 0.6 762.5 ± 26.2 0.95 ± 0.17 0.00 ± 0.00 0.015 ± 0.008 39.42 ± 0.94 13.35 ± 1.88
9 9.10 ± 0.04 5.82 ± 0.08 23.2 ± 0.0 962.0 ± 8.5 1.60 ± 0.51 3.28 ± 0.06 0.036 ± 0.005 41.60 ± 3.11 15.26 ± 1.05
10 9.84 ± 0.22 5.32 ± 0.33 22.5 ± 1.2 1,108.0 ± 72.4 1.15 ± 0.24 2.71 ± 0.50 0.050 ± 0.024 52.13 ± 1.22 13.88 ± 1.75
11 9.07 ± 0.66 5.49 ± 0.54 22.1 ± 3.9 1,265.8 ± 44.3 1.26 ± 0.22 0.42 ± 0.35 0.005 ± 0.001 55.48 ± 1.63 14.87 ± 0.38
12 9.11 ± 0.39 5.84 ± 0.35 22.4 ± 2.3 1,320.8 ± 28.2 1.23 ± 0.13 0.14 ± 0.10 0.006 ± 0.001 49.23 ± 5.22 14.47 ± 0.29
Values represent the mean ± SD of the values for 7 days.
HP, hydroponics; EC, electrical conductivity; TAN, total ammonia nitrogen.