Ozone has been regularly used as an aquatic ozidizer to decrease bacterial levels and increase water clarity since the early 1970s. However, it is not without risks, as it often narrows the aquatic biome, limits the bioavailability of iodine —a critical micronutrient —can damage gill epithelium, and, if unregulated, can cause immediate, widespread mortality. These challenges are discussed with the suggestion that dependence upon ozone become limited in the interest of improved fish health and welfare.