The most striking difference between the two treatments was in chloride concentration, for which all fifteen fish sampled in the high NO3-N group had values outside the i-Stat 1’s detection range (65 and 140 mmol/L), while all 15 fish in the low NO3-N group had expected values for whole blood chloride. Whetherchloride concentrations in the high NO3-N group were above orbelow instrument detection range cannot be determined