Table 3. Fish and crayfish NPK composition in a polyculture aquaponic system exposed to different light regimen (wet weight basis)

Parameter	Fish				Crayfish
	0 h	4 h	8 h	12 h	0 h	4 h	8 h	12 h
Initial N (mg/g)	2.06 ± 0.05	2.02 ± 0.05	2.02 ± 0.05	2.03 ± 0.04	2.02 ± 0.01	2.02 ± 0.02	2.03 ± 0.01	2.04 ± 0.02
Final N (mg/g)	2.95 ± 0.04a	2.93 ± 0.07a	2.97 ± 0.08a	2.97 ± 0.05a	2.60 ± 0.05x	2.61 ± 0.03x	2.65 ± 0.07x	2.64 ± 0.07x
Initial P (mg/g)	0.53 ± 0.02	0.57 ± 0.01	0.58 ± 0.0	0.59 ± 0.01	0.11 ± 0.02	0.10 ± 0.02	0.11 ± 0.01	0.11 ± 0.02
Final P (mg/g)	0.56 ± 0.04a	0.60 ± 0.01a	0.60 ± 0.01a	0.62 ± 0.01a	0.16 ± 0.01x	0.16 ± 0.0x	0.15 ± 0.0x	0.16 ± 0.01x
Initial K (mg/g)	0.25 ± 0.0	0.25 ± 0.01	0.25 ± 0.02	0.26 ± 0.01	0.04 ± 0.01	0.04 ± 0.02	0.04 ± 0.0	0.04 ± 0.01
Final K (mg/g)	0.27 ± 0.01a	0.26 ± 0.01a	0.27 ± 0.01a	0.28 ± 0.0a	0.06 ± 0.0x	0.06 ± 0.01x	0.06 ± 0.0x	0.05 ± 0.01x

Data are represented as mean ± SE.
Values within the same row and species with different superscript letters are significantly different (p < 0.05).
N, nitrogen; P, phosphate; K, potassium.