The high and low DO levels in the experiment were created
by applying different aeration regimes and by changing the
water flow rates. In addition to affecting the DO levels, the
contrast in water flow rates might have affected some of the
other water quality parameters which influence the feed intake
of fish. However, we think that these effects are negligible.
Temperature, nitrite and nitrate concentrations and pH were
within the optimal ranges for Nile tilapia (Masser et al., 1999;
Popma and Masser, 1999; Ross, 2000). Of all the water quality