In the current
study, the ORP of RAS-O3 and the oxygen con-
centrations in both RAS-C and RAS-O3 were well controlled. More
pure
oxygen
was injected into RAS-C than into RAS-O3 to maintain
similar oxygen concentrations. There were no significant differ-
ences in the measured nutrient parameters in the water, and the
biomasses of fish used in this study were well below the maximum
capacities of these RASs. However the water in RAS-O3 was clearer
than in RAS-C (visual inspection) presumably because of the strong
oxidative effect of ozone. A TRO of 0.06 mg L−1 was considered as
the safety limit for turbot (Reiser et al., 2011). During the whole
period
of our experiment, the TRO of the fish tanks in RAS-O3 did
not exceed 0.02 mg L−1, which is considered as safe