rows, serving as ‘blocks’. Within each block, the algae were stocked at
five densities, 0.2, 2, 4, 6 and 10 kg m−2. Each tank was supplied with
fish effluent at a rate of 100 L h−1. To keep the algae in circulation,
vigorous aerationwas supplied to each tank via a 1.2 cm (ID) polyethylene
hosewith 1.2 mmdiameter holeswith 2.5 cmspacing.