Epsom salt for constipation in bettas:
To give your fish an Epsom salt bath, pour half of the tank’s water into a clean container. Add 1 tablespoon of Epsom salt for every 1 gallon of water. Have the fish swim in the solution for 15 to 30 minutes. Remove the fish promptly and return him to his aquarium if he appears stressed or relieves himself.
Epsom salt for treating dropsy:
Tank the sick fish in a separate “hospital” tank, then adding Epsom salt at a rate of 1/8 teaspoon for every 5 gallons of water. The Epsom salt will relieve swelling. She also suggests feeding the fish a special diet containing antibiotics. Never use aquarium salt, or any other type of sodium, to treat a fish with dropsy: It may worsen the condition.
Epsom salt for swim bladder disorder in goldfish: Swim bladder disorder can strike all freshwater fish, but goldfish are especially prone to develop it. Fish with this condition have difficulty swimming upright because the swim bladder, which is normally filled with air, is compromised. Swim bladder disorder may be caused by gulping too much air, impacted eggs, infection, or constipation. Treat swim bladder disorder by skipping feedings for two to three days, then feeding a de-skinned pea. If that doesn’t help, increase the tank’s water temperature to between 78 and 80 degrees Fahrenheit and add Epsom salt at a rate of 1/8 teaspoon per 5 gallons of water.