Abstract

On an experimental fish farming system, two hydraulic retention times, above the normally used values, were tested to evaluate the effect on the growth of rainbow trout (Oncorhynchus mykiss) under normal conditions of production (>700 g), on the quality of water and on the productivity of the system. The results show that there are no differences on the growth between the groups of trout and also that the variables of quality of water remain in ranks suitable for cultivation. In terms of productivity, the use of higher water retention times for the growing of the trout (3h and 6h) allows to reduce its use, keeping adequate quality conditions, and increasing productivity when using a cultivation load between 2.5 and 5 times more than normally used.