Circular tank geometry is very common in aquaculture because it provides more stable flow patterns, more homogeneous
distribution of oxygen and metabolites, better self cleaning features, and higher average velocities than rectangular tanks,
thanks to the rotating flow characteristics.
CitacióMasaló, I., Oca, J. Fish swimming modifies flow pattern in aquacultural tanks. A: Aquaculture, Nature and Society. "EAS2015: Aquaculture, Nature and Society. Aquaculture Europe 15 Abstracts". Rotterdam: 2015, p. 489-490.