Pilot Plant Trial for Ozone Sterilization of Fish Hatchery Water

An ozone pilot plant was installed at the Dworshak National Fish Hatchery. to examine the efficacy of sterilizing makeup water entering this recycle hatchery. The pilot plant actually consisted of two separate systems operated together. A recycle system consisting of two fish tanks, a clarifier and biofilter was in operation prior to this study. An ozone system consisting of a Grace ozone generator (later replaced by a Welsbach generator) and a Grace contacting column was installed for this study. The ozone pilot plant supplied the makeup water to the existing recycle system. The pilot plant was run with approximately 125 pounds of cutthroat and one-half pound of steelhed fry. Recycle rate was 30 GPM and makeup rate was 3 GPM