This can be used in freshwater when starting a new aquarium, changing water, introducing new fish, treating sick fish, and when skin or fins are damaged.Makes tap water safe; immediately removes chlorine and chloramine, and neutralises heavy metals.Proven to reduce stress in fish by 40%.Promotes healing of wounds and regeneration of tissue (such as after illness, transport or fighting).Reduces the loss of electrolytes.Replace the natural slime coating fish need in times of stress & Neutralize chlorine & heavy metals in tap water