When treating Popeye, the disease caused by an iron deficiency in fish, it is important to use the right amount of Epsom salt. The recommended dose for Popeye treatment is 1 tablespoon per 10 gallons of water. This should be dissolved into a small container of aquarium water or dechlorinated tap water before being added to the tank. If possible, do not add any other medications such as antibiotics at this time. Epsom salt can be used up to twice a week until signs of improvement are seen and then decreased as needed. It is also wise to check with your local aquarium store for further instructions on how much Epsom salt you should add depending on your individual tank setup and type of fish present in order to make sure that you are giving them the best care possible!