Changing a fish's environment can cause stress, depriving it of vital nutrients and weakening its immune system. First Defense is scientifically formulated to relieve stress and support the immune system. It helps fish handle stress from bagging and shipping, water changes, adding new fish, disease treatments, and other environmental shifts.


To use Dr. Tim's Aquatics First Defense, just add it to your freshwater aquarium as directed on the bottle. This helps reduce fish stress and boost their immune system. Make sure to follow the dosage according to your tank size. When adding new fish or changing water, use it right away. Keep the product in a cool, dry place. If you have any questions or notice any issues with your fish, consult a vet or an aquarium expert.