Dr. Tim's Aquatics First Defense Fish Stress Relief & Immune Support for Freshwater Aquarium 16 fl. oz

Changing the environment of a fish causes stress that robs the fish of essential nutrients and can weaken their immune system. First Defense is scientifically designed to provide stress relief and support the immune system, helping fish cope with stress due to bagging and shipping from the store to your tank, water changes, new fish additions, disease treatments and other environmental changes.