The use of biofilter of aquatics plants can be an alternative for the treatment and minimization of effluents generated in fish farming. The objective of this work was to evaluate the effect of water hyacinth (Eichhornia crassipes) in the improvement of the limnological variables of water of supply channels used for fish farming. The experiment was conducted in supply channels over a period of 60-days at sampling intervals of fifteen days. The channels were sectioned with screens. A density of 120 fish m-³was used. The sections were divided into stages, alternating with presence or absence of water hyacinth. It was not observed significant differences in the level of ammonia (p >0.05), alkalinity and hardness of the effluent in both treatment systems. However it was observed that water hyacinth was efficient in the removal of nutrients such as, phosphorus (first weeks of cultivation). The use of water hyacinth can be recommended in fish farming systems.
Eichhornia crassipes; phosphorus; ammonia; water quality
