Statistical evaluation of growth did not yield differences between treatments and a potential difference in survival trended toward significance; however, the combined effect of slightly slower growth and decreased survival for the high NO3-N treatment resulted in significantly lower fish biomass and density. Mean rainbow trout biomass to conclude the study for the high and low NO3-N treatments was 332 ± 6 and 364 ± 9 kg per WRAS, respectively (P = 0.031). Mean fish density at the conclusion of the study was 64 ± 1 kg/m3 within the high NO3-N systems and 70 ± 2 kg/m3 within the low NO3-N systems (P = 0.035).