| The experimental unit used previously in our laboratory for the study of the effect of the photoperiod on the growth of flatfish was based on the use of tanks with separate recirculation systems. We modified it, connecting the different tanks to a single, more powerful recirculation system. This new unit comprised four different parts s - a biological filtar and an ultraviolet sterilizer. - a gravity operated water distribution system. - a series of 12 rearing tanks. - a piping system connecting the tank outlets to the biological filter. The total volume of the unit was 8 900 l. 200 l were changed every week. The main advantages of this new unit was that the quality of the water supplied to all tanks could be exactly the same, and that various parameters... |
