<b>Association between nocturnal and diurnal aeration in Nile tilapia rearing tanks

Resumo

The present study has assessed the benefits of the association between nocturnal and diurnal aeration of water on Nile tilapia´s culture tanks´ water and soil quality, as well as to fish growth performance. There were control tanks without mechanical aeration. In the nocturnal tanks, the aeration was provided daily from 22:00 h up to 06:00 h. The diurnal tanks were provided with aeration daily from 10:00 h up to 18:00 h. In the nocturnal and diurnal tanks, the culture water was aerated from 10:00 h up to 06:00 h. The concentration of NH₃ was significantly lower in the diurnal aerated, and nocturnal + diurnal aerated tanks when compared to the non-aerated tanks. The best water quality management to attain simultaneously high DO₂ and low NH₃ concentration was the nocturnal + diurnal aeration of water. The nocturnal + diurnal aeration of water has not shown any clear advantage on fish growth performance after 10 weeks when compared to the nocturnal aeration of water. It was concluded that the nocturnal + diurnal aeration of water is a water quality management superior to the nocturnal aeration because it achieves a better water quality