Table 3 Mean ± SEM of water quality parameters in different compartments of an aquaponic system combining both sampling times. Letters present the significant differences between the compartments of the system based on Kruskal-Wallis rank sum test followed by Fisher’s LSD test (α = 5%, n = 6)

Temp [°C]

26.9 ± 0.2ab

27.9 ± 0.3a

25.7 ± 0.5ab

25.1 ± 0.5b

25.4 ± 0.6b

24.9 ± 0.6b

26.1 ± 1.1ab

pH [−]

7.20 ± 0.03ab

7.33 ± 0.07a

7.27 ± 0.02a

7.24 ± 0.05a

7.09 ± 0.03b

7.08 ± 0.03b

7.34 ± 0.07a

EC [μS cm⁻¹]

1748 ± 65b

1743 ± 65b

1731 ± 64b

1721 ± 68b

1720 ± 71b

1716 ± 67b

2984 ± 42a

Oxygen [%]

107.7 ± 3.4a

99.2 ± 1.5a

101.9 ± 5.4a

80.7 ± 6.6b

41.5 ± 8.5c

36.1 ± 3.8c

1.8 ± 0.2d

Redox [mV]

105.4 ± 12.5a

112.9 ± 13.8a

94.8 ± 13.4a

99.9 ± 12.9a

69.1 ± 20.2ab

86.2 ± 15.7a

− 298.8 ± 8.0b

TOC [mg L⁻¹]

46.9 ± 3.6d

48.1 ± 3.6d

99.9 ± 4.5c

39.7 ± 2.0d

357.6 ± 200.8bc

131.6 ± 8.5b

3211.2 ± 258.2a

TN [mg L⁻¹]

129.5 ± 9.1bc

105.5 ± 11.7c

133.4 ± 7.9bc

138.9 ± 7.7b

135.3 ± 8.2ab

119.2 ± 7.1bc

613.7 ± 50.3a

NH₄⁺-N [mg L⁻¹]

0.23 ± 0.01bc

0.14 ± 0.03 cd

0.10 ± 0.01d

0.08 ± 0.01d

0.80 ± 0.51b

0.27 ± 0.07bc

215.06 ± 18.86a

NO₂⁻-N [mg L⁻¹]

0.05 ± 0.01c

0.06 ± 0.01bc

0.06 ± 0.01c

0.02 ± 0.00d

1.63 ± 0.57a

1.38 ± 0.39ab

0.08 ± 0.03 cd

NO₃⁻-N [mg L⁻¹]

132.8 ± 11.5bc

125.4 ± 10.2c

158.8 ± 4.7ab

180.9 ± 16.2a

135.23 ± 12.7abc

129.4 ± 18.3bc

0.5 ± 0.0d

Ca²⁺ [mg L⁻¹]

94.4 ± 4.4a

79.8 ± 3.2ab

65.6 ± 9.7ab

63.3 ± 7.7b

79.7 ± 4.5ab

81.1 ± 8.2ab

76.2 ± 4.5ab

Mg²⁺ [mg L⁻¹]

27.1 ± 1.2a

25.1 ± 0.8a

20.7 ± 3.4a

21.9 ± 4.0a

23.9 ± 1.0a

23.7 ± 1.6a

27.2 ± 2.0a

Na⁺ [mg L⁻¹]

207.9 ± 13.4a

213.1 ± 20.0a

175.6 ± 33.6a

149.4 ± 18.5a

172.5 ± 12.9a

175.5 ± 12.0a

164.6 ± 13.8a

K⁺ [mg L⁻¹]

60.9 ± 11.6a

93.8 ± 25.4a

70.9 ± 21.4a

52.9 ± 19.8a

36.5 ± 4.0a

55.4 ± 21.7a

68.7 ± 10.7a

SO₄²⁻-S [mg L⁻¹]

200.9 ± 42.1a

196.2 ± 14.9a

183.8 ± 63.4a

161.3 ± 59.2a

195.4 ± 53.2a

173.6 ± 41.3a

20.0 ± 0.3b