The hydroponic units (NFT) in this study consisted of two sources
of nutrient solution were used (1) Stock nutrient solution and (2)
Effluent fish farm, three lengths of gully (2, 3 and 4 m) and three water
flow rates 1, 1.5 and 2 L min-1. Intermitted flow (1 minute 'on' and 4
minute 'off') as described