The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems

► Ozonation of low exchange systems improved water quality. ► Ozonation of recirculating water significantly reduced TSS, BOD, Cu, Fe, and color. ► Fish grew significantly faster when systems were ozonated, all else equal. ► Fish grew as fast in ozonated systems as in systems flushed with 10 times more water.